Step-by-step explanation:
note that
sin²x = (1-cos²x)
LHS= cos²x - 2 sin²x
= cos²x - 2(1-cos²x)
= cos²x - 2 + 2cos²x
= 3cos²x - 2
or
cos²x = (1-sin²x)
LHS= cos²x - 2 sin²x
=1-sin²x - 2 sin²x
= 1-3sin²x
Answer:
There was a 5% change
Step-by-step explanation:
On Monday, the temperature was 80.
On Tuesday, the temp was 77
On Wednesday, the temp was 84
there was a difference of 4
4 is 5% of 80
The statement is expressed algebraically as
(x/43) - 87 = -75
