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Question : 17
Total: 50
The equation of the tangent to the curve y ( 1 + x 2 ) = 2 − x , where it crosses the X -axis is
Solution: 👈: Video Solution
We have, equation of the curve y ( 1 + x 2 ) = 2 − x . . . ( i )
∴ y ⋅ ( 0 + 2 x ) + ( 1 + x 2 ) ⋅
= 0 − 1 [on differentiating w.r.t.x]
⇒ 2 xy + ( 1 + x 2 )
= − 1
⇒
=
. . . (ii)
Since, the given curve passes throughx − axis i.e., y = 0 .
∴ O ( 1 + x 2 ) = 2 − x [using Eq.(i)]
⇒ x = 2
So, the curve passes through the point( 2 , 0 ) .
∴ (
) ( 2 , 0 ) =
= −
= slope of the curve
∴ slope of tangent to the curve = −
∴ Equation of tangent of the curve passing through ( 2 , 0 ) is
y − 0 = −
( x − 2 )
⇒ 5 y = − x + 2
⇒ 5 y + x = 2
Since, the given curve passes through
So, the curve passes through the point
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