the answer is D i added then subtracted
5) x=-4
6)p=8
7) x=40
8) a=5
9) b=16
10) q=2
The triangle is not a right angle
AC = 22 - 8 - 5 = 9
AC² = AB² + BC²
81 = 64 + 25
81 isn't equal to 89, the triangle is not a right angle
Answer:
see explanation
Step-by-step explanation:
Using the sum/ difference → product formula
cos x - cos y = - 2sin(
)sin (
)
sin x - sin y = 2cos (
)sin (
)
Given
(cosA - cosB)² + (sinA - sinB )²
= [ - 2sin(
)sin(
) ]² + [ 2cos(
)sin(
) ]²
= 4sin² (
)sin² (
) + 4cos² (
)sin² (
)
= 4sin² (
)[ sin² (
) + cos² (
) ← sin²x + cos²x = 1
= 4sin² (
) × 1
= 4sin² (
) = right side ⇒ proven