Answer:
B
Step-by-step explanation:
x² + 9x
to complete the square
add ( half the coefficient of the x- term )² to x² + 9x
= x² + 2(
)x + (
)²
= x² + 9x +
← the value of c
= (x +
)² ← a perfect square
Answer:
7
Step-by-step explanation:
7x2=14
5x7=35
Cos(θ) = -20/√((-20)^2 +(-21)^2)
.. = -20/-√841 . . . . . . . . . . . . . . . . . θ is a 4th-quadrant angle, so cos(θ) > 0
.. = 20/29
The value of the cosine is 20/29.
Can you tell us what the expression is in the question?