Calculus problem help

Question

Approximate the change in the function that occurs as x changes from x=7 x=6.99.

Answer 1

Since the derivative at x = 7 is 3, the exact value of the slope of the line tangent to the curve at x = 7 is 3.

so Δy = 3•(6.99 - 7.00) = 3•(-0.01) = - 0.03