Question

sabse smart kon aur kisme himeat hai pure queshion ko solve karne ke

Answer 1

No.6

sin 90=1
we know that if we get sum 90 when cos x+sin y then cos x=sin y
so cos 45=sin 45
cos 45 and sin 45=0.707106781
so
2*cos 45*sin 45=0.707106781²*2=1

we proved 2*cos 45*sin 45=1


No.7

As we know,
sin(90°-α) = cosα

∴sin30° = sin(90°-60°)
=cos60°
∵cos(40°+x) = sin30°
⇒cos(40°+x) = cos60°
⇒40°+x = 60°
⇒x = 20°


No.3

cos 60 is 1/2
cos30 is √3/2
sin60 is √3/2
sin30 is 1/2

so cos60 × cos 30 + sin60 × sin30 = 2×(√3/4)= √3/2
cosx = √3/2
therefore x = 60