If-parabola-y-x-2-2x-k-touches-the-parabola-y-1-2-x-2-4x-3-then-the-value-of-k-is-a-1-b-2-c-3-d-4-

Question Number 58400 by rahul 19 last updated on 22/Apr/19

I f p a r a b o l a y = - x^{2} - 2 x + k t o u c h e s

t h e p a r a b o l a y = - \frac{1}{2} x^{2} - 4 x + 3, t h e n

t h e v a l u e o f k i s ?

a) 1 b) 2 c) 3 d) 4

Commented by rahul 19 last updated on 22/Apr/19

i^{'} m g e t t i n g \frac{3}{2} b u t a n s . i s a! .

Answered by mr W last updated on 22/Apr/19

- x^{2} - 2 x + k = - \frac{1}{2} x^{2} - 4 x + 3

\frac{1}{2} x^{2} - 2 x + 3 - k = 0

x^{2} - 4 x + 2 (3 - k) = 0

Δ = 4^{2} - 4 \times 2 (3 - k) = 0

\Rightarrow k = 1

\Rightarrow a n s w e r (a)

Commented by rahul 19 last updated on 23/Apr/19

t h a n k s s i r!