Answer:
he made the error in step 2
Step-by-step explanation:
Answer:
1) solve x+1/x = 5






2) solve x³+1/x³

substitute x = 1/4 into the expression





Given:
The focus of the parabola is at (6,-4).
Directrix at y=-7.
To find:
The equation of the parabola.
Solution:
The general equation of a parabola is:
...(i)
Where, (h,k) is vertex, (h,k+p) is the focus and y=k-p is the directrix.
The focus of the parabola is at (6,-4).

On comparing both sides, we get

...(ii)
Directrix at y=-7. So,
...(iii)
Adding (ii) and (iii), we get



Putting
in (ii), we get



Putting
in (i), we get


Therefore, the equation of the parabola is
.
f(x) = -5x - 15
Let y = f(x)
y = -5x - 15
Switch the x and y places, and solve for y:
x = -5y - 15
-5y = x + 15
y = (x + 15)/-5
y = -(x/5) - 3
So the inverse of : f(x) = -5x - 15 is
-x/5 - 3