1.

Solve `sin^3thetacostheta-cos^3thetasintheta=1/4dot`

Answer» `sin^(3) theta cos theta-cos^(3) theta sin theta =1/4`
or `4 sin theta cos theta(sin^(2) theta - cos^(2) theta)=1`
or `2 sin 2 theta (-cos 2 theta)=1`
or `- sin 4 theta=1`
or `sin 4 theta=-1`
`rArr 4 theta=2 n pi - pi/2`
`rArr theta= (n pi)/2-pi/8, n in Z`


Discussion

No Comment Found