Answer:
Identity is verified.
Step-by-step explanation:
We have to verify the identity 
To prove any identity we always prove one side(either left hand side or right hand side) of the equation equal to the other side.
In this identity we take the left hand side first
(as we know cos(a+b) = cosa×cosb-sina×sinb)
= - sinx ( Right hand side)
Hence identity is proved.
Try this option:
the rule: if f(-x)=f(x), then the function f(x) is even, if f(-x)=-f(x) then the function is odd.
1. f(x)=-5x⁴-2;
if to substitute x→(-x), then f(-x)=-5*(-x)⁴-2; ⇔ f(-x)=-5x⁴-2, in other words f(x)=f(-x), it means that this function is even.
2. f(x)=x³+2x.
if to substitute x→(-x), then f(-x)=(-x)³+2*(-x); ⇔ f(-x)=-(x³+2x), in other words f(-x)=-f(x), it means that this function is odd.
Answer:
The value 4.5 is rational and the value 15−−√ is irrational. The sum of 4.5 and 15−−√ has a non-repeating and non-terminating decimal expansion. Therefore, the sum of 4.5 and 15−−√ is irrational. I can't explan but that's the correct Answer
Answer:
B
Step-by-step explanation:
<u>This is a right triangle as shown by the right angle.</u>
- The side opposite the right angle is the hypotenuse, which is 9.
- The side opposite angle A is 3.
So we have the opposite of A and the hypotenuse.
The trigonometric ratio that relates opposite side to hypotenuse is SINE.
Since, we need angle A, 
is A, opposite side is 3, and hypotenuse is 9, we substitute:
<em>To solve for the angle, we use our calculator and find the inverse sin of 
:</em>
<em>Rounding to nearest tenth of a degree:</em>
B is the right choice.
