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1. What are x-intercepts to the nearest hundredth of y=-33x² + 68x +13?

2. Factor and simplify the following: 16(3x+1)² - 25(y+3)²

3. Determine the nature of the roots of the quadratic equation below. -2x² + 3x + 8 =0

4. Determine the value of "k" for which 3x² - 5x + k = 0
asked Nov 10, 2014 in CALCULUS by anonymous

4 Answers

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(1)

The Equation is y = -33x²+68x+13

To find the X-intercepts of the Equation, we make y = 0.

-33x²+68x+13 = 0

To find the roots of the equation, we use the formula image where a= -33 , b = 68 and c = 13.

image

image

image

Roots are image and image

Roots are -0.17 and 2.23

Therefore x -intercepts points are (-0.17,0) and (2.23 , 0).

answered Nov 10, 2014 by Lucy Mentor
0 votes

(2)

The Expression is 16(3x+1)² - 25(y+3)².

16(3x+1)² - 25(y+3)²

= 16(9x²+1+6x) - 25(y²+9+6y)

= 144x² + 16 + 96x - (25y² + 225 + 150y)

= 144x² + 16 + 96x - 25y² - 225 - 150y

= 144x² - 25y² + 96x - 150y - 209

Therefore the simplified Expression is 144x² - 25y² + 96x - 150y - 209.

answered Nov 10, 2014 by Lucy Mentor
0 votes

(3)

The roots of the Quadratic equation is -2x² + 3x + 8 = 0.

To find the roots of the equation, we use the formula image where a= -2 , b = 3 and c = 8.

image

image

image

Roots are imageand image

Roots are -1.386 and 2.886

Therefore the nature of roots are real and irrational in nature.

answered Nov 10, 2014 by Lucy Mentor
0 votes

(4)

The Quadratic Expression is 3x² - 5x + k = 0.

To find the roots of the equation, we use the formula image where a= 3 , b = -5 and c = k.

image

image

There are three cases,

Case 1) image, then roots are real.

image

Case 2) image, then roots are equal.

image

Case 3) image, then roots are imaginary

image

Therefore the Value of the k depends on the nature of the root.

 

answered Nov 10, 2014 by Lucy Mentor

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