Hi there!
We are given:
cos(7x)cos(4x) = -1 - sin(7x)sin(4x)
Begin by moving all terms with variables to one side:
cos(7x)cos(4x) + sin(7x)sin(4x) = -1
The corresponding trig identity is cos(A - B). Thus:
cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1
cos(3x) = -1
cos = -1 at π, so:
3x = π
x = π/3
We can also find another solution. Let 3π = -1:
3x = 3π
x = π
Thus, solutions on [0, 2π) are π/3 and π.
Answer:
Obtuse Triangle
Step-by-step explanation:
When there is an angle with a measurement greater than 90 degrees, the triangle is an obtuse triangle.
Answer:
V=pi multiplied by r^2 times height
Step-by-step explanation:
It’s simple. The volume of a sphere is V=4/3πr^3.. so you will convert the mm to m okay?? 10mm=1cm .. so do your conversion from here then when you get the radius then you will substitute it into the volume where r is the radius.. so for the first one l changed mm to cm so.. radius is 4cm then l substitute it into the formula so l got 270 after rounding it to the nearest tenth.. pi=22/7 bear in mind. So do the same for the other one
