Warning: Illegal string offset 'html' in /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php on line 909

help - HSN forum

# help

5 replies to this topic

### #1south lanarkshire jag

Top of the Class

• Members
• 359 posts
• Gender:Male

Posted 11 November 2005 - 12:40 PM

can anyone help me with drawing the graph of 2x2(2= squared) -2x?

thanks

SLJ

### #2*sofax*

Child Prodigy

• Members
• 602 posts
• Location:Western Isles
• Interests:playing the fiddle, swimming, music, the OC, Will and Grace and going out with friends. Not that there is much to do here!!
• Gender:Female

Posted 11 November 2005 - 12:42 PM

what's the equation I'm confused by the way you have written it!
*a wee drop of heaven*

x sophie x

### #3south lanarkshire jag

Top of the Class

• Members
• 359 posts
• Gender:Male

Posted 11 November 2005 - 01:04 PM

(2x) all squared Subtract 2x

it's for a friend

### #4*sofax*

Child Prodigy

• Members
• 602 posts
• Location:Western Isles
• Interests:playing the fiddle, swimming, music, the OC, Will and Grace and going out with friends. Not that there is much to do here!!
• Gender:Female

Posted 11 November 2005 - 02:00 PM

with the x being squared it sounds to me like it should be an up right parabola!
*a wee drop of heaven*

x sophie x

### #5aldo

Good Effort

• Members
• 56 posts
• Location:West Lothian
• Gender:Male

Posted 11 November 2005 - 03:05 PM

You can use software such as Excel (or your calculator) taking set values of x and calculating the corresponding y value.

I have attached what it should look like.

### #6dfx

Fully Fledged Genius

• Members
• 1,955 posts
• Gender:Male

Posted 11 November 2005 - 06:12 PM

Just a quick run through of teh sketching procedure:

x = 0 or x = 1.

So now you know it cuts the x-axis through 0 and 1.

It cuts the y-axis when x = 0, so y = 0 also.

Lastly, find the turning points by differentiating and setting the derivative = 0.

So the x-coordinate of the turning point is x = 1/2 . For the y-coordinate:

So the turning point is (1/2 , -1/2).

Finally, you know its a parabola because it's a degree 2 polynomial, and that it has a minimum turning point (i.e. it's U shaped because the coefficient of x is positive).

#### 1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users