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Mathematics 16 Online
OpenStudy (liv1234):

HELP ASAP PLEASE

OpenStudy (liv1234):

OpenStudy (vishweshshrimali5):

The correct method: 1. Find out dy/dx 2. Put dy/dx = 0 and solve for x 3. Find out d^2 y/dx^2 ... 4. Put the values of x you obtained from step 2 in expressions from step 3 5. If d^2 y/dx^2 < 0 => Maximum at that point; if d^2 y/dx^2 > 0 => Minimum at that point... I won't go deep into d^2 y/dx^2 = 0

OpenStudy (liv1234):

Would the answer be C?

OpenStudy (vishweshshrimali5):

dy/dx = -2x + 4 = 0 => x = 2 d^2 y/dx^2 = -2 At x = 2, d^2 y/dx^2 < 0 => Maximum y @ x = 2 is -4 + 8 - 4 = 0 So you are partially correct.. the correct answer is A

OpenStudy (liv1234):

Okay, thank you! Can you help me with a similar question, please?

OpenStudy (vishweshshrimali5):

Sure

OpenStudy (liv1234):

OpenStudy (vishweshshrimali5):

What do you think?

OpenStudy (vishweshshrimali5):

What is dy/dx here?

OpenStudy (liv1234):

I think B

OpenStudy (vishweshshrimali5):

Nope

OpenStudy (vishweshshrimali5):

How did you get it?

OpenStudy (liv1234):

Ohh wait, I was looking at the question wrong!

OpenStudy (liv1234):

Can you give me a hint?

OpenStudy (vishweshshrimali5):

Yeah sure First find out dy/dx... You will get dy/dx = x + 8 Put it equal to 0, find out the value of x Then find out d^2y/dx^2

OpenStudy (liv1234):

Ohh would it be C? Because 8-8=0?

OpenStudy (vishweshshrimali5):

Wait what is d^2y/dx^2 ?

OpenStudy (liv1234):

I'm not sure.

OpenStudy (vishweshshrimali5):

Okay can you find out x from dy/dx = 0 ?

OpenStudy (liv1234):

No, I'm confused on what dy/dx is

OpenStudy (vishweshshrimali5):

You have done calculus right?

OpenStudy (liv1234):

No. I'm only in Algebra 2.

OpenStudy (vishweshshrimali5):

Oops!! My mistake then...

OpenStudy (vishweshshrimali5):

Okay so we have another option...|dw:1459349375053:dw|

OpenStudy (vishweshshrimali5):

Now the above was the graph when a is positive When a is -ve the graph becomes: |dw:1459349456360:dw|

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