it is true
Y=1/2 c + 1=81 so the answer is a-True
Let z = sin(x).
.. z^2 -2z = 2
.. z^2 -2z +1 = 3
.. (z -1)² = 3
.. z -1 = ±√3
.. z = 1 -√3 . . . . . the positive solution is extraneous
sin(x) = 1 -√3
To solve A, complete the square for both variables.
The center is (6,4)
Ratio is 5girls:7boys with total 72 students
5+7= 12
72➗12= 6
6(5:7)= 30 girls : 42 boys
New ratio is 3:4 with 48 boys
48➗4= 12
So for girls 3x12= 36
So started with 30 girls ended with 36 girls... 6 girls joined band during the school year.