find the exact value of the expression do not use a calculat

find the exact value of the expression. do not use a calculator.( complementary angles theorem)

i need help step by step.

cos35 sin55 + sin35 cos55

Solution

To solve the given expression we need to use the angle sum identiy:

sinA cosB+ cosA sinB= sin (A+B)

so using this identiy we get

cos35 sin55 + sin35 cos55= sin (55+35)

=sin(90^o)

=1. Answer.