Conic Sections Question 76
Question: If the line $ y=mx+c $ is a tangent to the parabola $ y^{2}=4a(x+a) $ then $ ma+\frac{a}{m} $ is equal to
Options:
A) c
B) 2c
C) - c
D) 3c
Show Answer
Answer:
Correct Answer: A
Solution:
Tangent at $ y^{2}=4ax $ is $ y=mx+\frac{a}{m} $
Therefore, tangent at $ y^{2}=4a(x+a) $ is, $ y=m(x+a)+\frac{a}{m} $
or $ y=mx+ma+\frac{a}{m} $
therefore $ ma+\frac{a}{m}=c $ .
BETA
