Answer:
Because θ lies in quadrant II, 2θ must lie in quadrant IV. This means the tangent of 2θ is negative.
The adjacent side to θ is 7 because √(25²-24²)=7, so tanθ=7/24.
The double angle formula for tangent is tan 2θ = (2 tan θ) / (1 − tan² θ).
Substituting the value for tanθ in and keeping in mind that this is in quadrant IV, we get tan 2θ = -(2(7/24)/(1-(7/24)²)).
Simplified, this becomes tan 2θ = -336/527.
Therefore, the answer is C. -336/527.
He subtracted the 29fron the 30
I'm assuming the given log equation is 
If so, then the exponential form is 
This is because the general form
transforms into 
For both equations, the 'b' is the base.
Given:
The increase in pressure P is the linear function of the depth d.

The cost of dinner is $300 and $10 per students.
To find:
The initial value and rate of change and their interpretation.
Find the cost function C where n is the number of students.
Solution:
The slope intercept form of a linear function is
...(i)
where, m is rate of change and b is y-intercept or initial value.
We have,
...(ii)
From (i) and (ii), we get

The initial value is 14.7. It means, the pressure at sea level is 14.7 pounds psi.
Rate of change is 0.445. It means, the pressure is increasing by 0.445 pounds psi for every feet.
The cost of dinner is $300 and $10 per students.
Let C(n) be the total cost for dinner and n be the number of students.
Fixed cost = $300
Additional cost for 1 student = $10
Additional cost for n student = $10n
Now,
Total cost = Fixed cost + Additional cost

Therefore, the required cost function is
.