Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identity
sin²x + cos²x = 1 , then
sin²x = 1 - cos²x and cos²x = 1 - sin²x
Consider the left side
← expand numerator/denominator using FOIL
=
= 
= 
= 
= cot²A = right side , thus proven
I think it might be -38, not 100% though.
The ball takes approximately a time of 2.041 seconds to reach its maximum height.
<h3>What time does the ball take to reach maximum height?</h3>
The height of the ball as a function of time is modelled by a <em>quadratic</em> equation, the required information can be found by transforming the expression into <em>vertex</em> form:
h = - 4.9 · t² + 20 · t + 12
h = - 4.9 · (t² - 4.082 · t - 2.449)
h + (- 4.9) · (6.615) = - 4.9 · (t² - 4.082 · t + 4.166)
h - 32.414 = - 4.9 · (t - 2.041)²
The ball takes approximately a time of 2.041 seconds to reach its maximum height.
To learn more on quadratic equations: brainly.com/question/1863222
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Cups of flour=15 3/4=15+ 3/4=(4*15+3)/4=63/4
Cups of sugar=10 1/2=(2*10+1)/2=21/2
We solve this problem by rule of 3:
63/4 cups of flour--------------100 people
x------------------------------------ 25 people
x=(63/4 cups of flout * 25 people)/100 people=1575/400 cups of flour=
=63/16=(3*16+15)/16=3 15/16 cups of flour.
21/2 cups of sugar-----------------100 people
x-----------------------------------------25 people
x=(21/2 cups fo sugar * 25 people) / 100 people=525/200 cups of sugar= 21/8 =(2*8+ 5)/8=2 5/8 cups of sugar.
Answer: 3 15/16 cups of flour and 2 5/8 cups of sugar.