The answer is C, 25% increase. To find the increase, subtract starting value (780) from the final value (975). It equals out to be 195. Divide 195 by the starting value which turns out to be 0.25. Then, multiply 0.25 by 100 which equals out to be 25.
Answer:

Step-by-step explanation:
For this case we know that:

And we want to find the value for
, so then we can use the following basic identity:

And if we solve for
we got:


And if we replace the value given we got:

For our case we know that the angle is on the II quadrant, and on this quadrant we know that the sine is positive but the cosine is negative so then the correct answer for this case would be:

3- What number, when multiplied by 4, equals -24?
Hope this helps. :)