Using the unit circle, you can visualise the secant as follows:
- Draw the vertical line passing trough (1,0)
- Extend the radius until it meets this line at point P
- The length of OP is the secant of your angle.
Since -90 means that the radius points downwards, it means that the radius is vertical as well, and thus it never meets the vertical line through (1,0).
Thus, the secant is not defined at -90.
In fact, if we switch back to the function notation, we can confirm this claim, since we have

which is undefined.
Answer:
Percentage increase in the height is 55%.
Step-by-step explanation:
Since Cindy is growing plants for a science project. During the project Cindy found that one plant grows from 7 cm to 10.85 cm.
We have calculate percent increase in the height of the plant.
We know formula to calculate the percentage is
% Increase in the height = Net increase in the height×100/Initial length of the plant
= 
Therefore % increase in the height of the plant is 55%.
Answer:
Mr.Walters car can go 15 miles on one gallon of gas.
Step-by-step explanation:
To find this, you first want to put it into a ratio.
480:32
Next, you want to divide.
480/32
After you divide, you get 15. That tells you that you get 15 miles off of one gallon of gas.