Let,
y=tan(4x)^tan(5x)y=tan(4x)tan(5x)
Taking natural log. ,both sides
lny=lntan(4x)^tan(5x)lny=lntan(4x)tan(5x)
lny=tan(5x)*lntan(4x)lny=tan(5x)⋅lntan(4x)
Diff.w.r.t xx ,Using Product Rule:
1/y(dy)/(dx)=tan(5x)d/(dx)(lntan(4x))+lntan(4x)d/(dx)(tan(5x))1ydydx=tan(5x)ddx(lntan(4x))+lntan(4x)ddx(tan(5x))
1/y(dy)/(dx)=tan(5x)*4/tan(4x)sec^2(4x)+lntan(4x)5sec^2(5x)1ydydx=tan(5x)⋅4tan(4x)sec2(4x)+lntan(4x)5sec2(5x)
1/y(dy)/(dx)=4tan(5x)cos(4x)/sin(4x)xx1/cos^2(4x)+5sec^2(5x)lnt
an(4x)1ydydx=4tan(5x)cos(4x)sin(4x)×1cos2(4x)+5sec2(5x)lntan(4x)
1/y(dy)/(dx)=(4tan(5x))/(sin(4x)cos(4x))+5sec^2(5x)lntan(4x)1ydydx=4tan(5x)sin(4x)cos(4x)+5sec2(5x)lntan(4x)
(dy)/(dx)=y{(4tan(5x))/(sin(4x)cos(4x))+5sec^2(5x)lntan(4x)}dydx=y{4tan(5x)sin(4x)cos(4x)+5sec2(5x)lntan(4x)}