What is the equation of the tangent line of the one-family of curve x^2 + y^2 = 25 at

P(4, 3) ??

help please

3 answers

Use implicit differentiation to get
2x+2yy'=0
from which
y'=-x/y=-4/3
The tangent line is therefore
(y-3)=(-4/3)(x-4)
Simplify if necessary.
I have 3 choices for that

A 4x -3y + 25 = 0
B 4x + 3y - 25 = 0
C 3x + 4y -24 = 0

i dunno what is the correct answer
Expand (y-3)=(-4/3)(x-4)
and move all the terms to the left hand side, and you should find that the equation matches one of the answers.

If it does not, post what you've got.