Question

Q. (sin A + cos A)2 is equal to
A) sin2 A + cos2 A
C)sin2 A - cos2 A
B) 1+ 2 sin A.cos A
D) 1 - sin A. Cos À​

Answer 1

Answer:

B) 1+2sin A.cos A

Step-by-step explanation:

We know that,

${(a + b) }^{2} = {a}^{2} + {b}^{2} + 2ab$

Here a=sinA , b=sinB

${( \sin( \alpha ) + \sin( \beta ) ) }^{2}$

=>

${ \sin( \alpha ) }^{2} + { \sin( \beta ) }^{2} + 2 \sin( \alpha ) . \sin( \beta )$

We know that,

${ \sin( \alpha ) }^{2} + { \sin( \beta ) }^{2} = 1$

Therefore,

$1 + 2 \sin( \alpha ) . \sin( \beta )$