Answer:
True
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (- 4, - 9), thus
y = a(x + 4)² - 9
To find a substitute the coordinates of the zero (- 7, 0) into the equation.
0 = a(- 7 + 4)² - 9, that is
0 = 9a - 9 ( add 9 to both sides )
9a = 9 ( divide both sides by 9 )
a = 1, thus
y = (x + 4)² - 9 ← expand factor using FOIL
y = x² + 8x + 16 - 9
y = x² + 8x + 7
The expression cos⁴ θ in terms of the first power of cosine is <u>[ 3 + 2cos 2θ + cos 4θ]/8.</u>
The power-reducing formula, for cosine, is,
cos² θ = (1/2)[1 + cos 2θ].
In the question, we are asked to use the formulas for lowering powers to rewrite the expression in terms of the first power of cosine cos⁴ θ.
We can do it as follows:
cos⁴ θ
= (cos² θ)²
= {(1/2)[1 + cos 2θ]}²
= (1/4)[1 + cos 2θ]²
= (1/4)(1 + 2cos 2θ + cos² 2θ] {Using (a + b)² = a² + 2ab + b²}
= 1/4 + (1/2)cos 2θ + (1/4)(cos ² 2θ)
= 1/4 + (1/2)cos 2θ + (1/4)(1/2)[1 + cos 4θ]
= 1/4 + cos 2θ/4 + 1/8 + cos 4θ/8
= 3/8 + cos 2θ/4 + cos 4θ/8
= [ 3 + 2cos 2θ + cos 4θ]/8.
Thus, the expression cos⁴ θ in terms of the first power of cosine is <u>[ 3 + 2cos 2θ + cos 4θ]/8</u>.
Learn more about reducing trigonometric powers at
brainly.com/question/15202536
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Answer:
13.76
Step-by-step explanation:
Area of the whole
The area of the whole = s^2 (the firgure is a square
s = 8
Area of the whole = 8^2 = 64
Area of the unshaded part
The 2 half circles = 1 whole circle
The radius of the 1/2 circle = 4 (eight has been cut in half)
Area of two half circles = 2* (pi r^2/2)
Area of two half circles = 2 * (pi 4^2/2)
area of two half circles = 16*pi
Area of the shaded area
Area of the shaded area = area of the whole - area of the unshaded area
Area of the shaded area = 64 - 16*pi
Area of the shaded area = 64 - 3.14*16 = 13.76
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Hope this helps