Answer:
y = -3/4 x + 25/2
Step-by-step explanation:
x² + y² = 100
Take derivative with respect to x.
2x + 2y dy/dx = 0
2y dy/dx = -2x
dy/dx = -x/y
Evaluate at (6, 8).
dy/dx = -6/8
dy/dx = -3/4
Use point-slope form to write equation:
y − 8 = -3/4 (x − 6)
Simplify.
y − 8 = -3/4 x + 9/2
y = -3/4 x + 25/2