<em>solution</em><em> </em><em>:</em><em>-</em><em>-</em>
Answer:
10cos(5x)sin(10x) = 5[sin (15x) + sin (5x)]
Step-by-step explanation:
In this question, we are tasked with writing the product as a sum.
To do this, we shall be using the sum to product formula below;
cosαsinβ = 1/2[ sin(α + β) - sin(α - β)]
From the question, we can say α= 5x and β= 10x
Plugging these values into the equation, we have
10cos(5x)sin(10x) = (10) × 1/2[sin (5x + 10x) - sin(5x - 10x)]
= 5[sin (15x) - sin (-5x)]
We apply odd identity i.e sin(-x) = -sinx
Thus applying same to sin(-5x)
sin(-5x) = -sin(5x)
Thus;
5[sin (15x) - sin (-5x)] = 5[sin (15x) -(-sin(5x))]
= 5[sin (15x) + sin (5x)]
Hence, 10cos(5x)sin(10x) = 5[sin (15x) + sin (5x)]
The rock will hit the ground at 2 seconds.
Explanation:
Given that the height, h, in feet of a rock above the ground is given by the equation
, where t is the time in seconds after the rock is thrown.
We need to determine the time at which the rock will hit the ground.
To determine the time, let us equate the height h = 0 in the equation
, we get,
![0=-16t^2+24t+16](https://tex.z-dn.net/?f=0%3D-16t%5E2%2B24t%2B16)
Switch sides, we have,
![-16 t^{2}+24 t+16=0](https://tex.z-dn.net/?f=-16%20t%5E%7B2%7D%2B24%20t%2B16%3D0)
Let us solve the equation using the quadratic formula.
Thus, we have,
![t=\frac{-24 \pm \sqrt{24^{2}-4(-16) 16}}{2(-16)}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-24%20%5Cpm%20%5Csqrt%7B24%5E%7B2%7D-4%28-16%29%2016%7D%7D%7B2%28-16%29%7D)
Simplifying, we get,
![t=\frac{-24 \pm \sqrt{576+1024}}{-32}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-24%20%5Cpm%20%5Csqrt%7B576%2B1024%7D%7D%7B-32%7D)
![t=\frac{-24 \pm \sqrt{1600}}{-32}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-24%20%5Cpm%20%5Csqrt%7B1600%7D%7D%7B-32%7D)
![t=\frac{-24 \pm 40}{-32}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-24%20%5Cpm%2040%7D%7B-32%7D)
Hence, the two values of t are
and ![t=\frac{-24 -40}{-32}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-24%20-40%7D%7B-32%7D)
Simplifying the values, we get,
and ![t=\frac{-64}{-32}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-64%7D%7B-32%7D)
Dividing, we get,
and ![t=2](https://tex.z-dn.net/?f=t%3D2)
Since, t cannot negative values, we have,
![t=2](https://tex.z-dn.net/?f=t%3D2)
Thus, the rock will hit the ground at 2 seconds.
Answer:
24.30 Difference, sale price 56.70
Step-by-step explanation:
30% off 81.00 is 56.70
The difference is 24.30