Chapter 3
Precalculus: Functions and Graphs · 268 exercises
Problem 1
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(u\) is directly proportional to \(v .\) If \(v=30,\) then \(u=12\)
6 step solution
Problem 1
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$3+2 i; \quad \text { degree } 2$$
6 step solution
Problem 1
(a) Sketch the graph of \(f\). (b) Find the domain \(D\) and range \(R\) of \(f .\) (c) Find the intervals on which \(f\) is increasing or is decreasing. $$f(x)=\frac{4}{x}$$
7 step solution
Problem 1
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-1,2,3 ; \quad f(-2)=80$$
4 step solution
Problem 1
Sketch the graph of \(f\) for the indicated value of \(c\) or \(a\) $$f(x)=2 x^{3}+c$$ (a) \(c=3\) (b) \(c=-3\)
4 step solution
Problem 1
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=2 x^{4}-x^{3}-3 x^{2}+7 x-12 ; \quad p(x)=x^{2}-3$$
8 step solution
Problem 2
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. s varies directly as \(t .\) If \(t=10,\) then \(s=18\)
4 step solution
Problem 2
(a) Sketch the graph of \(f\). (b) Find the domain \(D\) and range \(R\) of \(f .\) (c) Find the intervals on which \(f\) is increasing or is decreasing. $$f(x)=\frac{1}{x^{2}}$$
6 step solution
Problem 2
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-5,2,4 ; \quad f(3)=-24$$
6 step solution
Problem 2
Sketch the graph of \(f\) for the indicated value of \(c\) or \(a\) $$f(x)=-2 x^{3}+c$$ (a) \(c=-2\) (b) \(c=2\)
6 step solution
Problem 2
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=3 x^{4}+2 x^{3}-x^{2}-x-6 ; \quad p(x)=x^{2}+1$$
8 step solution
Problem 3
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(r\) varies directly as \(s\) and inversely as \(t .\) If \(s=-2\) and \(t=4\) then \(r=7\)
4 step solution
Problem 3
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$2,-2-5 i; \quad \text { degree } 3$$
5 step solution
Problem 3
Identify any vertical asymptotes, horizontal asymptotes, and holes. $$f(x)=\frac{-2(x+5)(x-6)}{(x-3)(x-6)}$$
4 step solution
Problem 3
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-4,3,0 ; \quad f(2)=-36$$
6 step solution
Problem 3
Sketch the graph of \(f\) for the indicated value of \(c\) or \(a\) $$f(x)=a x^{3}+2$$ (a) \(a=2\) b) \(a=-\frac{1}{3}\)
6 step solution
Problem 3
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=3 x^{3}+2 x-4 ; \quad p(x)=2 x^{2}+1$$
6 step solution
Problem 4
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$-3,1-7 i; \quad \text { degree } 3$$
5 step solution
Problem 4
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(w\) varies directly as \(z\) and inversely as the square root of \(u\) If \(z=2\) and \(u=9,\) then \(w=6\)
3 step solution
Problem 4
Identify any vertical asymptotes, horizontal asymptotes, and holes. $$f(x)=\frac{2(x+4)(x+2)}{5(x+2)(x-1)}$$
4 step solution
Problem 4
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-3,-2,0 ; \quad f(-4)=16$$
5 step solution
Problem 4
Sketch the graph of \(f\) for the indicated value of \(c\) or \(a\) $$f(x)=a x^{3}-3$$ (a) \(a=-2\) b) \(a=\frac{1}{4}\)
5 step solution
Problem 4
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=3 x^{3}-5 x^{2}-4 x-8 ; \quad p(x)=2 x^{2}+x$$
6 step solution
Problem 5
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$-1,0,3+i ; \quad \text { degree } 4$$
5 step solution
Problem 5
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(y\) is directly proportional to the square of \(x\) and inversely proportional to the cube of \(z .\) If \(x=5\) and \(z=3,\) then \(y=25\)
4 step solution
Problem 5
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-2 i, 2 i, 3 ; \quad f(1)=20$$
7 step solution
Problem 5
Use the Intermediate value theorem to show that \(f\) has a zero between \(a\) and \(b\) $$f(x)=x^{3}-4 x^{2}+3 x-2 ; \quad a=3, \quad b=4$$
5 step solution
Problem 5
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=7 x+2 ; \quad p(x)=2 x^{2}-x-4$$
3 step solution
Problem 6
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$0,2,-2-i; \quad \text { degree } 4$$
4 step solution
Problem 6
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(q\) is inversely proportional to the sum of \(x\) and \(y .\) If \(x=0.5\) and \(y=0.7,\) then \(q=1.4\)
6 step solution
Problem 6
Find a polynomial \(f(x)\) of degree 3 that has the indicated zeros and satisfies the given condition. $$-3 i, 3 i, 4 ; \quad f(-1)=50$$
5 step solution
Problem 6
Use the Intermediate value theorem to show that \(f\) has a zero between \(a\) and \(b\) $$f(x)=2 x^{3}+5 x^{2}-3 ; \quad a=-3, \quad b=-2$$
4 step solution
Problem 6
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=-5 x^{2}+3 ; \quad p(x)=x^{3}-3 x+9$$
4 step solution
Problem 7
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$4+3 i,-2+i ; \text { degree } 4$$
4 step solution
Problem 7
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(z\) is directly proportional to the product of the square of \(x\) and the cube of \(y .\) If \(x=7\) and \(y=-2,\) then \(z=16\)
5 step solution
Problem 7
Sketch the graph of \(f\) $$f(x)=\frac{3}{x-4}$$
5 step solution
Problem 7
Find a polynomial \(f(x)\) of degree 4 with leading coefficient I such that both \(-4\) and 3 are zeros of multiplicity 2 and sketch the graph of \(f .\)
9 step solution
Problem 7
Use the Intermediate value theorem to show that \(f\) has a zero between \(a\) and \(b\) $$f(x)=-x^{4}+3 x^{3}-2 x+1 ; \quad a=2, \quad b=3$$
4 step solution
Problem 7
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=9 x+4 ; \quad p(x)=2 x-5$$
4 step solution
Problem 8
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$3+5 i,-1-i ; \text { degree } 4$$
5 step solution
Problem 8
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(r\) is directly proportional to the product of \(s\) and \(v\) and inversely proportional to the cube of \(p\). If \(s=2, v=3,\) and \(p=5,\) then \(r=40\)
3 step solution
Problem 8
Sketch the graph of \(f\) $$f(x)=\frac{-3}{x+3}$$
5 step solution
Problem 8
Find a polynomial \(f(x)\) of degree 4 with leading coefficient 1 such that both \(-5\) and 2 are zeros of multiplicity 2 and sketch the graph of \(f\).
6 step solution
Problem 8
Use the Intermediate value theorem to show that \(f\) has a zero between \(a\) and \(b\) $$f(x)=2 x^{4}+3 x-2 ; \quad a=\frac{1}{2}, \quad b=\frac{3}{4}$$
5 step solution
Problem 8
Find the quotient and remainder if \(f(x)\) is divided by \(p(x)\). $$f(x)=7 x^{2}+3 x-10 ; \quad p(x)=x^{2}-x+10$$
5 step solution
Problem 9
A polynomial \(f(x)\) with real coefficients and leading coefficient 1 has the given zero(s) and degree. Express \(f(x)\) as a product of linear and quadratic polynomials with real coefficients that are irreducible over \(\mathbb{R}\). $$0,-2 i, 1-i ; \quad$ \text { degree }5$$
4 step solution
Problem 9
Exer. 1-12: Express the statement as a formula that involves the given variables and a constant of proportionallty \(k,\) and then determine the value of \(k\) from the given conditions. \(y\) is directly proportional to \(x\) and inversely proportional to the square of \(z .\) If \(x=4\) and \(z=3,\) then \(y=16\)
5 step solution
Problem 9
Sketch the graph of \(f\) $$f(x)=\frac{-3 x}{x+2}$$
6 step solution
Problem 9
Find a polynomial \(f(x)\) of degree 6 such that 0 and 3 are both zeros of multiplicity 3 and \(f(2)=-24 .\) Sketch the graph of \(f\).
7 step solution
Problem 9
Use the Intermediate value theorem to show that \(f\) has a zero between \(a\) and \(b\) $$f(x)=x^{5}+x^{3}+x^{2}+x+1 ; \quad a=-\frac{1}{2}, \quad b=-1$$
5 step solution