Problem 126

Question

If \(f(x)=3 x+7,\) find \(\frac{f(a+h)-f(a)}{h}\)

Step-by-Step Solution

Verified
Answer
The derivative of \(f(x) = 3x + 7\) using the difference quotient formula is 3.
1Step 1: Substitute f(a) into the expression
Substitute \(a\) into the function \(f(x) = 3x + 7\). This gives \(f(a) = 3a + 7\).
2Step 2: Substitute f(a+h) into the expression
Substitute \(a+h\) into the function \(f(x) = 3x + 7\). This gives \(f(a+h) = 3(a+h) + 7 = 3a + 3h + 7\).
3Step 3: Substitute f(a+h) and f(a) into the expression
Substitute \(f(a+h)\) and \(f(a)\) into the difference quotient formula \(\frac{f(a+h)-f(a)}{h}\). This gives \(\frac{3a + 3h + 7 - (3a + 7)}{h} = \frac{3h}{h} = 3\).