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!
Hello! Congruent figures are those with the same size and shape. With that being said, if you look at the shapes correctly, here are your answers:
Quad 1 & 2: Not Congruent
Quad 1 & 3: Congruent
Quad 1 & 4: Congruent
Quad 2 & 3: Not Congruent
Quad 2 & 4: Not Congruent
Quad 3 & 4: Congruent
The answer is 45x+y=-226. Hope this helps :)
Answer:
y = 218
Step-by-step explanation:
Mean = (Sum of all numbers)/(How many numbers present)
27 = (20 + 2y + 25 + y + 30)/27
27 = (3y + 75)/27
3y + 75 = 729
3y = 729 - 75
3y = 654
y = 218
notice, is an arithmetic sequence, simply adding 6 to get the next term's value.
