Question

if sin a = a/b , then cos a =?​

Answer 1

$\boxed{\huge{\bf{\purple{ANSWER:}}}}$

$cos \ a=\dfrac{\sqrt{b^2-a^2}}{b}$

Step by step solution:

$Given \ sin \ a=a/b\\\\we \ have \ to \ find \ cos \ a\\\\Let \ us \ do\\\\we \ know \ sin \ a=P/H=a/b \ and \ cos \ a=B/H\\\\H^2=B^2+P^2\\\\B=\sqrt{H^2-P^2}\\\\B=\sqrt{b^2-a^2}\\\\ we \ have \ cos \ a\ B/H\\\\putting \ value \ here\\\\cos \ a=\dfrac{\sqrt{b^2-a^2}}{b}$

Answer 2

Hii its tom85

Sin a = a/b

Squirting on both side

Sin^2a = (a/b)^2

1 - cos^2 a= (a/b)^2

Cos^2a = 1 - (a/b)^2

Cos a = {sqrt (b^2 - a^2)}/b