sin45cos25 + cos45sin25 = ??
a. cos70
b. sin70
c. cos20
d. sin 20
which answer is correct ??
sin a cos b + cos a sin b =
you do this one
= sin (a+b) = sin 70
Is that right Damon ?
Yes, correct
To solve this problem, we can use the trigonometric identity for the sum of two angles:
sin(A + B) = sin(A)cos(B) + cos(A)sin(B)
In this case, we have sin(45°)cos(25°) + cos(45°)sin(25°).
By comparing this with the trigonometric identity, we can see that A = 45° and B = 25°.
Using the identity sin(A + B), we substitute A = 45° and B = 25° into the formula, giving us:
sin(45° + 25°) = sin(70°)
So, the correct answer is (b) sin70.