Answer:
x = 1
y = -3
Step-by-step explanation:
cos(pi) = -1
so many ways :
sqrt(0.5/2) = sqrt(0.5/2 × 8/8) = sqrt(4/16)
= sqrt(0.5/2 × 18/18) = sqrt(9/36)
= sqrt(1/4) = 1/2
"nicest" approach (all integers) :
3x² = sqrt(9)
3x² = 3
x² = 3/3 = 1
x = 1
2y = sqrt(36)
2y = 6
y = 6/2 = 3
one of them has to be negative (because cos(pi) = -1), so it has to be y, because 3x² cannot be negative with real numbers.
so, y = -3
-1 × 3×1²/(2×-3) = sqrt(0.5/2) = 1/2
-1 × 3/-6 = 1/2
3/6 = 1/2
1/2 = 1/2
correct
