It would take 24 mins to drive 28 miles going 70mph
Answer:80
Step-by-step explanation:
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:
A. 25 B. 45 C. 30
Step-by-step explanation:
A.
75 ÷ 3 = 25
25 × 1 = 25
B.
75 ÷ 5 = 15
15 × 3 = 45
C.
50 ÷ 5 = 10
10 × 3 = 30
→ Substitute cos 2x and sin 2x by their expressions
→ Subtract both sides by sin x
→ Take sin x as a common factor in the right side
From the graph, the equation has 4 solutions, the intersection points between the 2 graphs
