Answer:
on what do you need help in
Answer:
See the proof below.
Step-by-step explanation:
For this case we need to proof the following indentity:
So we need to begin with the definition of tangent, we know that 
and we can do this:
(1)
We also have the following identities:
Now we can apply those identities into equation (1) like this:
(2)
We can divide numerator and denominator from expression (2) by 
we got this:
And simplifying we got:
And that complete the proof.
Height of the woman = 5 ft
Rate at which the woman is walking = 7.5 ft/sec
Let us assume the length of the shadow = s
Le us assume the <span>distance of the woman's feet from the base of the streetlight = x
</span>Then
s/5 = (s + x)/12
12s = 5s + 5x
7s = 5x
s = (5/7)x
Now let us differentiate with respect to t
ds/dt = (5/7)(dx/dt)
We already know that dx/dt = 7/2 ft/sec
Then
ds/dt = (5/7) * (7/2)
= (5/2)
= 2.5 ft/sec
From the above deduction, it can be easily concluded that the rate at which the tip of her shadow is moving is 2.5 ft/sec.
Answer:
8h + 15 = 39
Step-by-step explanation:
The base fee is 15 so you shouldn't multiply the hours by it.
The question states 8 per hour which means that you should multiply the 8 by hours and add on the base fee which is 15.
5353 minutes = 89.22 hours
Maybe the figures should be 53 and 20??
Let's let Billy = A
The formula to use for work problems is
Time = (A*B) / (A+B)
53 = ( (A +20)* A) / (A +20 + A) )
53 = ( A^2 + 20A ) / (2A + 20)
A^2 + 20A -106A -1060
A^2 -86A -1060
A = 96.935
Bobby Mows in 116.935 minutes
