(i)
I=∫0π/2(sinx)cosx(cosxcotx−log(sinx)sinx)dx=∫0π/2dxd(sinx)cosxdx=1
(ii) The point of intersection of
−4y2=xandx−1=−5y2 is
(−4,−1)and(−4,1).
Hence, required area
=2{∫01(1−5y2)dy−∫01−4y2dy}=34.
(iii) The point intersection of
y=3x−1logxandy=xx−1 is
(1,0).
Hence,
dxdy=x3x−1+3x−1⋅log3⋅logx∴(dxdy)(1,0)=1For\therefore \quad\left(\frac{d y}{d x}\right)_{(1,0)}=
1If\theta
isanglebetweenthecurves,then\tan \theta=0
.∵\theta=
0∘(iv)dxdy=x+y2⇒dydx−2x=2y⇒xe−y/2=21⋅\inty\cdote−y/2dy⇒x+y+2=key/2⇒k=3∴x+y+2=3ey/2$[passing through (1,0) ]