Question

sin A. cotA=cos A.
prove it using identities​

Answer 1

♣ Qᴜᴇꜱᴛɪᴏɴ :

$\large\boxed{\sf{\mathrm{Prove\:}\sin \left(a\right)\cot \left(a\right)=\cos \left(a\right)}}$

★═════════════════★

♣ ᴀɴꜱᴡᴇʀ :

$\mathrm{Manipulating\:left\:side}$

$\sin \left(a\right)\cot \left(a\right)$

$\text { Use the following identity: } \cot (x)=\dfrac{\cos (x)}{\sin (x)}$

$\cot \left(a\right)\sin \left(a\right)=\dfrac{\cos \left(a\right)}{\sin \left(a\right)}\sin \left(a\right)$

$\large\boxed{=\cos \left(a\right)}$

L.H.S = R.H.S

Hence Proved !!!!