A.)

Use the identities

and

on the left-hand side

Make 1 have a common denominator to allow for fraction subtraction
Multiply the numerator and denominator of 1 by cos^2 x

Use Pythagorean identity for the numerator.
If

then subtracting both sides by

yields

. We can substitute that into the numerator

======
b.)

For the left-hand side:
By definition,

and

Since

Using Pythagorean identity,

so
In the equationn = negative 1
You can multiply 10 by 1/4 or .25
10x.25=2.5
The answer is 447 because you got to add 35 plus 410
first find the number of adults in the city then find the number of people who support power plant and if the precent adults in the city is 100% then take the number of people that support power plants and find out what precent of adults In the city are power plant supporters.