[MOVED, MERGED] Find min on graph y=x^2 - 5x, etc.

[mathsishard]

Hi, I'm doing Maths A level and am having the promblem of understanding maths in lessons, but as soon as i do my homework, struggle to get the answer! Please could you help me with the questions below! Thank you SO MUCH!

1)Find the minimum point on the graph y=x^2 - 5x. Use your answer to find the value of k for which the equation x^2 -5x = k

2) USe the graph of y=4x-3x^2 to find the values of k for which the equation 3x^2 - 4x =K =0 has no real roots.

3) THe graph of y=x^4 -2x^3 -2x^2 is used to find solutions of the equation x^4-2x^3 -2x^2= k for various values of k.
a)find the maximum and miimum points
B)find the co-ordinates where the graph meets the x axis.
c) find the number of roots when k is : a) 4 b) -4 c) -8
D) for what values of k does the equation have : a) 0 b) 1 c)2 d)3 e) 4 real roots

THANK YOU!!

 

[mathsishard]

Please Help me! I've been trying for nearly 2 hours!

Hi, I'm doing Maths A level and am having the promblem of understanding maths in lessons, but as soon as i do my homework, struggle to get the answer! Please could you help me with the questions below! Thank you SO MUCH!

1)Find the minimum point on the graph y=x^2 - 5x. Use your answer to find the value of k for which the equation x^2 -5x = k

2) USe the graph of y=4x-3x^2 to find the values of k for which the equation 3x^2 - 4x =K =0 has no real roots.

3) THe graph of y=x^4 -2x^3 -2x^2 is used to find solutions of the equation x^4-2x^3 -2x^2= k for various values of k.
a)find the maximum and miimum points
B)find the co-ordinates where the graph meets the x axis.
c) find the number of roots when k is : a) 4 b) -4 c) -8
D) for what values of k does the equation have : a) 0 b) 1 c)2 d)3 e) 4 real roots

THANK YOU!!

 

[mathsishard]

Can't help if we can't see your work...

Oh sorry...I wasn't really sure how this worked so just posted the questions.

For each question, I am able to differentiate to dy/dx. I know from there, I need to factorise and equate to zero, but am having difficulty doing so. Thank you for answering!

 

[stapel]

I'm...having the promblem of understanding... as soon as i do my homework, struggle to get the answer!

You already have loads of worked examples in your textbook and in your class notes, so looking at another completed solution isn't likely to help at all. Therefore, kindly please reply showing some of those struggles, so that we can try to figure out exactly where you're running into problems. Thank you!

1)Find the minimum point on the graph y=x^2 - 5x.

Hint: What technique has your class discussed, at length, which relates to max/min points?

2) USe the graph of y=4x-3x^2 to find the values of k for which the equation 3x^2 - 4x =K =0 has no real roots.

Hint: What is the graphical interpretation of "real roots"? What did you see when you looked at the graph of y?