Consider the LHS of the given equation $4(\cos^310^\circ+\sin^320^\circ)=3(\cos10^\circ+\sin20^\circ)$ $\text{LHS} = 4(\cos^310^\circ+\sin^320^\circ)$ since $\sin30=\cos60^\circ=\frac{1}{2}$ and $\sin60^\circ=\cos30^\circ=\frac{\sqrt{3}}{2}$ $\Rightarrow\sin3.20^\circ=\cos3.10^\circ$ $\Rightarrow3\sin20^\circ-4\sin^320^\circ=4\cos^310^\circ-3\cos10^\circ$ $\Rightarrow4(\cos^310^\circ+\sin^320^\circ)=3(\cos10^\circ+\sin20^\circ)$ $=\text{RHS}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.