We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2
So,
cos 130 + cos 110 + cos 10
cos 130 + 2cos (110+10)/2 × cos( 110-10)/2
cos 130 + 2cos 60 × cos 50
cos ( 180 - 50 ) + 2cos60 cos 50
We know, cos ( 180 - A ) = -cos A
2cos 60 cos 50 - cos 50
Also, cos 60 = 0.5
2×0.5 cos 50 - cos50
cos 50 - cos 50
0 = RHS.
Hence proved
Here there are 20 members in all.
Each member paid $2.60.
Total amount paid by members = 20 × 2.60 = $52
The club paid $47.50 to hire the hall. ......Answer
Hence the amount received by the hall = 52 - 4.50 = $ 47.50
The Hall charged $47.50 as the fee.
Answer:
Step-by-step explanation:
A is 180 degrees, B is 180 degrees, C is definition of complementary angle, D is 180-angle 2, and E is angle 3.
Answer:
Step-by-step explanation:
Given
Required
The exponent form
We have:
Apply the following law of indices;
So, the expression becomes:
