Question

If cos A = 5/13, then find cosA+sinA​

Answer 1

cos A=5/13

sinA= √13²-5²/13

=12/13

therefore cosA +sinA =5/13+12/13

=17/13

Answer 2

Answer:

cosec A + cot A = 5 ⇒ cotA = 5 – cosecA

Squaring both the sides, we get

⇒ cot2 A =(5 – cosecA)2

⇒ cot2 A = 25 + cosec2A – 10cosec A

⇒ cosec2 A – 1 = 25 + cosec2A – 10cosec A

[∵ 1+ cot2 A = cosec2 A]

⇒ –1 – 25 = –10cosecA

⇒ – 26 = –10cosec A

Now, cosec A + cot A = 5