Question

sinA+cosA=1, find Angle =A

Answer 1

sinA + cosA = 1
if A = 0 degree
then 
sin 0 + cos 0 = 0+1 =1  0 is possible
if A =90 degree
then sin90 + cos 90 = 1 + 0 = 1
So for angle A = 0 or 90 degree

Answer 2

HeY!!

SinA + cosA = 1

Squaring on both side

(SinA + cosA )² = 1²

Sin²A + cos²A + 2sinA×cosA = 1

1 + 2sinA×cosA = 1²

2sinA×cosA = 1 - 1

Sin2A = 0 [ •°• 2sinA×cosA = sin2A ]

sin2A = 0

Sin2A = sin0°

2A = 0

A = 0/2 = 0°


For verification

From LHS

sin0° + cos0°

0 + 1 = 1 = RHS prooved
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Hope it helps you !!

@Rajukumar111