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!
Answer:
405 of the students
Step-by-step explanation:
Answer:
Radius : 3 inches
Height : 2 inches
Step-by-step explanation:
![π \times (radius {)}^{2} \times (height)](https://tex.z-dn.net/?f=%CF%80%20%5Ctimes%20%28radius%20%7B%29%7D%5E%7B2%7D%20%20%5Ctimes%20%28height%29)
![π \times {3}^{2} \times 2](https://tex.z-dn.net/?f=%CF%80%20%5Ctimes%20%20%7B3%7D%5E%7B2%7D%20%20%5Ctimes%202)
![π \times 9 \times 2](https://tex.z-dn.net/?f=%CF%80%20%5Ctimes%209%20%5Ctimes%202)
![9 \times π \times 2](https://tex.z-dn.net/?f=9%20%5Ctimes%20%CF%80%20%5Ctimes%202)
![18\pi](https://tex.z-dn.net/?f=18%5Cpi)
<h3>Hope it is helpful...</h3>
Answer for teardrop shape:
64.27
Step-by-Step Explanation:
I used the area calculators on Goggle
Answer for square:
5.7
Explanation:
The shape is a square, so all the sides are equal
5.7 + 6.8 = 12.5
x = 5.7
Answer for trapezoid:
76.95
Explanation:
Again, Goggle
The expression is equivalent to 49/8.