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:
(10, 14)
Step-by-step explanation:
To solve this system let's use substitution:
Solve the first equation for x, obtaining x = 24 - y, and then substitute 24 - y for x in the second equation:
3(24 - y) + 5y = 100
Performing the indicated multiplication, we get:
72 - 3y + 5y = 100
Combining like terms results in 72 - 100 = -2y, or -28 = -2y
Thus, y must be 14.
If y = 14, then the first equation tells us that x = 10.
Check: Is this true? 3(10) + 5(14) = 100 YES
The solution is (10, 14).
What was it about the questions on the best that you were supposed to compare to this solution?
Part A: Shiloh would collect data on which student spends the most time at the beach
Part B: It is a statistical question
Answer:
My bid was $42 less than the winning bid.
Step-by-step explanation:
The winning bid is x.
$28 is 40% of x
0.4x = 28
x = 28/0.4
x = 70
The winning bid was $70.
$70 - $28 = $42
Answer: My bid was $42 less than the winning bid.
