5cos (2x)+7=cos (2x)+8, 4cos (2x)=1, cos (2x)=1/4, 2x=arccos(1/4), x=(1/2)arccos (1/4). I used x instead of theta, and arccos is cos inverse
(1 - 2x)⁴
(1 - 2x)(1 - 2x)(1 - 2x)(1 - 2x)
[1(1 - 2x) - 2x(1 - 2x)][1(1 - 2x) - 2x(1 - 2x)]
[1(1) - 1(2x) - 2x(1) - 2x(-2x)][1(1) - 1(2x) - 2x(1) - 2x(-2x)]
(1 - 2x - 2x + 4x²)(1 - 2x - 2x + 4x²)
(1 - 4x + 4x²)(1 - 4x + 4x²)
1(1 - 4x + 4x²) - 4x(1 - 4x + 4x²) + 4x²(1 - 4x + 4x²)
1(1) - 1(4x) + 1(4x²) - 4x(1) - 4x(-4x) - 4x(4x²) + 4x²(1) - 4x²(4x) + 4x²(4x²)
1 - 4x + 4x² - 4x + 16x² - 16x³ + 4x² - 16x³ + 16x⁴
1 - 4x - 4x + 4x² + 16x² + 4x² - 16x³ - 16x³ + 16x⁴
1 - 8x + 24x² - 32x³ + 16x⁴
A cube has 6 sides on it. Just think of a dice.
Hope I Helped!!!
The length of hypotenuse of an isosceles right triangle with two equal legs each 4 cm is given by Pythagorean theorem as follows.
√42+42.
=√32.
=4√2.
4√2 cm.
