One way it's useful is in the application of phasors in physics. Phasors require you to add up vectors of two different angles, so the cosine angle addition formula can be used if you already know the cosine and sine of the original vector angles.
Answer:
-2x+1
Step-by-step explanation:
Step-by-step explanation:
sin(x)=±9/41
As x lies in Quadrant 4 , sin(x) = -9/41
Answer:
(x-1) (x-4) is the answer
Answer:
A = 22.5 m²
Step-by-step explanation:
longest side length
b = √((-7 + 4)² + (-1 - 8)²) = √90
other sides
a = √((-1 + 7)² + (2 + 1)²) = √45
height
h = √((√45)² - (½√90)²) = √22.5
Area of triangle
A = ½bh = ½√90√22.5 = 22.5 m²
a little math shows that this triangle is a tilted half of a square with sides √45
