Question

please answer fast I'll mark you brainliest​

Answer 1

Answer:

ok mark it brainlist then I will give your answer ....promise

Answer 2

Step-by-step explanation:

➜cos(a+b)=cos(a)cos(b)-sin(a)sin(b)

→cos(60°)cos(30°)-sin(60°)sin(30°)

→cos(60°+30°)

→cos(90°)

→0