# Thread: Tangent Prob.

1. ## Tangent Prob.

Estimate the slope of the tangent line at P by averaging the slopes of two secant lines.
P (15,250)
Slope of two secant lines are -38.8 and -27.8

The answer is -33.3. I cant seem to achieve this answer I keep getting -5.5, I am just adding both slopes and diving by 2.

2. Hello flutterby
Originally Posted by flutterby
Estimate the slope of the tangent line at P by averaging the slopes of two secant lines.
P (15,250)
Slope of two secant lines are -38.8 and -27.8

The answer is -33.3. I cant seem to achieve this answer I keep getting -5.5, I am just adding both slopes and diving by 2.
You're getting a sign wrong. When you add -38.8 and -27.8, the answer is -66.6, not -11.

Grandad