[falafels]

The function m(x) = x²-6x+5 (xER, x is greater than or equal to a)

State the least value of a and hence determine the equation of inverse m(x). State its domain.

I've done complete the square to find the least value of a=-2

How do you get the inverse equation? (btw, the answer is:

inverse m(x) = √(x-5) - 2)

[Christophicus]

Originally Posted by falafels

The function m(x) = x²-6x+5 (xER, x is greater than or equal to a)

State the least value of a and hence determine the equation of inverse m(x). State its domain.

I've done complete the square to find the least value of a=-2

How do you get the inverse equation? (btw, the answer is:

inverse m(x) = √(x-5) - 2)

Right, you've typed out the question wrong.

m(x) = x²+4x+9

It amazes me how people expect others to help them when they do this.

[falafels]

Oh, woops! So I have! :o

But I'm still stuck on it....

[Christophicus]

Originally Posted by falafels

The function m(x) = x²+4x+9 (xER, x is greater than or equal to a)

State the least value of a and hence determine the equation of inverse m(x). State its domain.

I've done complete the square to find the least value of a=-2

How do you get the inverse equation? (btw, the answer is:

inverse m(x) = √(x-5) - 2)

m(x) = (x+2)²-4+9 x >/= a
m(x) = (x+2)²+5

m(x) a minimum when (x+2)² = 0
=> x+2 = 0
=> x = -2 = a

m(x) = (x+2)²+5
(x+2)² = m(x)-5
x+2 = √(m(x)-5)
x = -2+√(m(x)-5)

Inverse function is reflected in the line y = x
So replace m(x) with x and x with m^-1(x)

m^-1(x) = -2+√(x-5)

Inverse function is real as long as xER and x>/=5

[mizfissy815]

m(x)= (x+2)² + 5
y = (x+2)² + 5
Rearrange to make y the subject of the formula-
y-5= (x+2)²
√(y-5) -2 = x
Now change y to x-
m^-1(x) = √(x-5) -2