Answer:
B.
Step-by-step explanation:
Total surface area of the square pyramid
= 4 times the area of one triangle + Area of square

4 sin^2 θ + 13cos^2 θ = 7
sin^2 θ = 1 - cos^ θ
4 - 4cos^2 θ + 13cos^2 θ = 7
9cos^2 θ = 3
cos^2 θ = 1/3
cos θ = # (1/3) # - square root
Square root of (1/3) has +1/3 and -1/3 as values of cos
Find the key angle by doing the cos inverse of #1/3
K.A = cos^-1 #(1/3) = 0.955
θ lies in all 4 quadrants
The values of θ are:
θ = 0.955, 2.186, 4.096, 7.23
Ignore 0.955, 2.186, 4.096, 7.23 as they are out of range pi/2 = 1.571
The the value of θ = 0.955 = 0.96 (to 2 d.p) radian
Hope it helped!
If you would like to know how many pages can Henry write in 8 hours, you can calculate this using the following steps:
5 1/4 = 21/4 pages ... 3 hours
x pages = ? ... 8 hours
21/4 * 8 = 3 * x
21 * 2 = 3 * x
3 * x = 42
x = 42 / 3
x = 14 pages
Henry can write 14 pages of his novel in 8 hours.
We know that in 2020 the population of deer will be 900,000 based on the given numbers. In another 5 years the population will be over 1 million (1,350,000) in order to calculate when it will reach 1 million we need to see how much growth is gained per year. I believe to obtain that information we will need to divide 450,000 by 5 that equals 90,000 a year. So if I’m 2020 the population of deer will be 900,000 than add 90,000 until you reach your 1 million marker. In this case 2021 would be 990,000 thousand so 2022 would be 1,080,000. So your answer should be year 2022. Hope that helps.