<h3>
Answer: Rhombus and square</h3>
Explanation:
Any rhombus has its diagonals meet at 90 degree angles. The proof for this is a bit lengthy, so I'll let you handle it. The basic idea is to draw in the diagonals, which forms smaller triangles. Proving those triangles to be congruent leads to supplementary congruent angles, which in turn leads to the 90 degree angles needed.
A square is a special type of rhombus where all four angles are the same (each 90 degrees). Put another way, a square is both a rectangle and a rhombus at the same time.
Some rectangles are not squares, so the non-square rectangles will have the diagonals not be perpendicular.
Answer:
5.92 min
Step-by-step explanation:
1/11 = person A's rate
1/21 = person B's rate
1/33 = person C's rate
Let t = time working to gether
rt = am't of work done
(1/11)t = work done by person A
(1/21)t = work done by person B
(1/33)t = work done by person C
(1/11)t + (1/21)t + (1/33)t = 1
231((1/11)t + 231(1/21)t + 231(1/33)t = 231
21t + 11t + 7t = 231
39t = 231
t = 5.92 min
I did that in super detail for you. Note: If n = the time to do a job alone, then 1/n = the rate of speed in doing the job. And, the rate times the time on the job = am't of work done.
There are four solutions for the <em>trigonometric</em> equation 2 · cos x = 4 · cos x · sin² x are x₁ = π/4 ± 2π · i, x₂ = 3π/4 ± 2π · i, x₃ = 5π/4 ± 2π · i and x₄ = 7π/4 ± 2π · i, 
.
<h3>How to solve a trigonometric equation</h3>
In this problem we must simplify the <em>trigonometric</em> equation by both <em>algebraic</em> and <em>trigonometric</em> means and clear the variable x:
2 · cos x = 4 · cos x · sin² x
2 · sin² x = 1
sin² x = 1/2
sin x = ± √2 /2
There are several solutions:
x₁ = π/4 ± 2π · i,
x₂ = 3π/4 ± 2π · i,
x₃ = 5π/4 ± 2π · i,
x₄ = 7π/4 ± 2π · i,
There are four solutions for the <em>trigonometric</em> equation 2 · cos x = 4 · cos x · sin² x are x₁ = π/4 ± 2π · i, x₂ = 3π/4 ± 2π · i, x₃ = 5π/4 ± 2π · i and x₄ = 7π/4 ± 2π · i, .
To learn more on trigonometric equations: brainly.com/question/27821667
#SPJ1
Answer:
5
Step-by-step explanation:
