SOLUTION: Once again I am asking for some help. Home school book question reads as such.WRITE THE MINIMUM OR MAXIMUM POINT FOR EACH FUNCTION, AND GIVE THE COORDINATES FOR THAT POINT. 1. y=3x

Algebra ->  Graphs -> SOLUTION: Once again I am asking for some help. Home school book question reads as such.WRITE THE MINIMUM OR MAXIMUM POINT FOR EACH FUNCTION, AND GIVE THE COORDINATES FOR THAT POINT. 1. y=3x      Log On


   

Question 159977: Once again I am asking for some help. Home school book question reads as such.WRITE THE MINIMUM OR MAXIMUM POINT FOR EACH FUNCTION, AND GIVE THE COORDINATES FOR THAT POINT. 1. y=3x^2 -6x=9 ___ HINT:START AT -1 AND INCREASE. 2. y=x^2 -4x +1 _____ HINT: START AT 0 AND INCREASE 3. y=x^2 -8x -5 ___ HINT: START AT 2 AND INCREASE 4. y= -x^2 +2x+6 ____ HINT: START AT-1 AND INCREASE. IF THERE IS ANYONE THERE THAT UNDERSTANDS THIS I COULD REALLY USE YOUR HELP. THANKS FOR TAKING THE TIME TO READ THIS.
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
You are being asked to use trial and error to grind out the answer.
Let's do 1, then you can do the others
y=3x^2 -6x + 9 ___ HINT:START AT -1 AND INCREASE.
at x=-1
y+=+3%28-1%29%5E2+-6+%2A%28-1%29+%2B+9
y+=+3+%2B+6+%2B+9
y+=+18
at x=0
y+=+3%2A%280%29%5E2+-6%2A%280%29+%2B+9
y+=+9
at x = 1
y+=+3%281%29%5E2+-6+%2A%281%29+%2B+9
y+=+3+-+6+%2B+9
y+=+6
at x =2
y+=+3%282%29%5E2+-6+%2A%282%29+%2B+9
y+=+3%2A4+-+12+%2B+9
y+=+9
So you can already see the minimum is somewhere between 0 and 2. As far as integers go, that is 1. In fact, the number IS 1.
Another way to check this is to plot it.
You can use a graphing calculator or something like geogebra. (geogebra is freee to download)
graph%28400%2C400%2C+-10%2C10%2C+-10%2C10%2C+3x%5E2-6x%2B9%29
Do the same process for the other problems

Grinding answers this way is never much fun. But is sometimes required. All it takes is a persistence. Happy grinding :)