Question

SinA+cosA=√2,sin2Ais equal to ,

Answer 1

Square it

(sin A + cos A) ^2 = (root 2)^2


sin^2 A + cos ^2 A + 2 sin A cos A = 2

1 + 2 sin A cos A = 2

2 sin A cos A = 1

sin 2A = 1

Thats the answer

Answer 2

hay!!

Dear friend -

if we square both sides we get our answer

here is ur answer

$(sina + cosa) {}^{2} = ( \sqrt{2} ) {}^{2}$

$sin {}^{2}a + cos {}^{2} a + 2sina \: cosa = 2$

$1 + 2sina \: cosa = 2$

2sina cosa = 1

sin2a = 1