Straight Line Question 222
Question: Locus of centroid of the triangle whose vertices are $ (\alpha cost,asint),(bsint,-bcost) $ and $ (1,0) $ , where t is a parameter, is
Options:
A) $ {{(3x+1)}^{2}}+{{(3y)}^{2}}=a^{2}-b^{2} $
B) $ {{(3x-1)}^{2}}+{{(3y)}^{2}}=a^{2}-b^{2} $
C) $ {{(3x-1)}^{2}}+{{(3y)}^{2}}=a^{2}+b^{2} $
D) $ {{(3x+1)}^{2}}+{{(3y)}^{2}}=a^{2}+b^{2} $
Correct Answer: C $ \Rightarrow a\cos t+b\sin t=3x-1 $ $ y=\frac{a\sin t-b\cos t}{3}\Rightarrow a\sin t-b\cos t=3y $ Squaring & adding, $ {{(3x-1)}^{2}}+{{(3y)}^{2}}=a^{2}+b^{2} $
Show Answer
Answer:
Solution:
BETA
