After substituting:

Factor out the 36, allowing the 6's to cancel

Use trig identity:
sec^2 - 1 = tan^2
9514 1404 393
Answer:
11.8
Step-by-step explanation:
The number has no digits to the right of the tenths place, so the number is correctly rounded as is.
11.8
Answer:
15
Step-by-step explanation:
Put the given value of x where x is in the expression and do the arithmetic.
4^3 -(3 +4)^2 = 64 -49 = 15
The value of the expression for x=4 is 15.