You have
.. f'(u) = sec(u)^2
Putting in u = g(x) = x^9, this becomes
.. f'(g(x)) = sec(x^9)^2
You know
(f(g(x))' = f'(g(x))*g'(x) . . . . . chain rule
From previous results, this is
.. sec(x^9)^2*9x^8
Answer: 21
Step-by-step explanation:
Given : The scores on the midterm exam are normally distributed with

Let X be random variable that represents the score of the students.
z-score: 
For x=82

For x=90

Now, the probability of the students in the class receive a score between 82 and 90 ( by using standard normal distribution table ) :-

Now ,the number of students expected to receive a score between 82 and 90 are :-

Hence, 21 students are expected to receive a score between 82 and 90 .
The answer
3. measure of DEA is 43°
proof: 90° +47° + mDEA= 180°, so mDEA= 43°
2.complementary angle
1.corresponding angles
If its a parent then the answer would be 60
Answer: 89.6 kg of water
Step-by-step explanation:
Find the total volume of the tank:
(80cm)*(35cm)*(40cm) = 112,000 cm^3
4/5 of this would be 89,600 cm^3
Water has a mass of 1 gram/cm^3
(1 gram/cm^3)*(89,600 cm^3) = 89,600 g of water
(89,600 g)*(1 kg/1,000 g) = 89.6 kg of water