JEE Main 2022 · 25 June · Evening Shift · Mathematics · Application of Derivatives
If the angle made by the tangent at the point ( x _ 0 , y _ 0 ) on...
If the angle made by the tangent at the point (x0,y0) on the curve x=12(t+sintcost),<br/>y = 12{\left(1 + \sin t\right)}^{2}, 0 < t <\dfrac{\pi}{2},withthepositivex-axis is \dfrac{\pi}{3}, then y0 is equal to
Options
A6(3+22)
B3(7+43)
C27
D48
Correct answer
C. 27
Step-by-step solution
Given,
Curve x=12(t+sintcost)
y=12(1+sint)2
Now dxdy=dtdxdtdy
tan(3π)=dtd(12(t+sintcost))dtd(12(1+sint)2)
3=12(1+cos2t)12×2(1+sint)(cost)
3=2cos2t2(1+sint)⋅cost
3=cost1+sint=cos22t−sin22t(cos2t+sin2t)2
3=tan(2t+4π)
3π=2t+4π⇒2t=12π⇒t=6π
Now putting t=6π in y = 12{\left(1 +\text{ \sin t }\right)}^{2}</p><p>as(x0,y0) lie on curve