If the slope of the curve $y=\frac{a x}{b-x}$ at the point (1, 1) is 2 , then
Answer & explanation
Correct answer: option 3
We have,
$y=\frac{a x}{b-x}$ at point (1, 1)
$⇒1=\frac{a}{b-1}$ so $b-1=a$ so $b=a+1$ ...(1)
Slope = 2 at (1, 1)
so $yb-yx=ax$
differentiating ⇒ $y'(b-x)-y=a$
at (1, 1)
$⇒ 2'(b-1)-1=a$
$y'=2$
from (1) $b-1=a$
so $2a-1=a$
$⇒a=1$
so from (1) $b=2$