Changing the order of the denominator doesn’t change the product. 4•6=24 and 6•4=24 again.
There are 2 tangent lines that pass through the point

and

Explanation:
Given:

The point-slope form of the equation of a line tells us that the form of the tangent lines must be:
![[1]](https://tex.z-dn.net/?f=%5B1%5D)
For the lines to be tangent to the curve, we must substitute the first derivative of the curve for
:



![[2]](https://tex.z-dn.net/?f=%5B2%5D)
Substitute equation [2] into equation [1]:
![[1.1]](https://tex.z-dn.net/?f=%5B1.1%5D)
Because the line must touch the curve, we may substitute 

Solve for x:




± 
±
<em> </em>

There are 2 tangent lines.

and

Answer: 4.5 days or 4 1/2 days
Step-by-step explanation: We can use cross product property, to solve this. Workers to Days remember that
9x - y = 15
2x + 8y = 28
Use the substitution method.
Solve for y in the first equation.
9x - y = 15
-y = 15 - 9x
y = -15 + 9x
Now plug in y into the second equation.
2x + 8(-15 + 9x) = 28
2x - 120 + 72x = 28
74x - 120 = 28
74x = 148
x = 2
Plug x back into the rewritten first equation.
y = -15 + 9(2)
y = -15 + 18
y = 3
x = 2, y = 3
The slope of the line is 2/3, so the angle is arctan(2/3) ≈ 33.69°.