{l}{(1)sin^4alpha-cos^4alpha=2sin^2alpha-1}{(2)sinθ(1+tanθ)+cosθ(1+1/tanθ)=1/sinθ+1/cosθ} সমাধান কৰক

$$\left. \begin{array} { l } { ( 1 ) \sin ^ { 4 } \alpha - \cos ^ { 4 } \alpha = 2 \sin ^ { 2 } \alpha - 1 } \\ { ( 2 ) \sin \theta ( 1 + \tan \theta ) + \cos \theta ( 1 + \frac { 1 } { \tan \theta } ) = \frac { 1 } { \sin \theta } + \frac { 1 } { \cos \theta } } \end{array} \right.$$

α, θ-ৰ বাবে সমাধান কৰক

$$\theta =2\pi n_{1}+\frac{3\pi }{4}\text{, }n_{1}\in \mathrm{Z}\text{, }\alpha \in \mathrm{R}$$

$$\theta =2\pi n_{2}+\frac{7\pi }{4}\text{, }n_{2}\in \mathrm{Z}\text{, }\alpha \in \mathrm{R}$$