Wednesday

April 23, 2014

April 23, 2014

Posted by **mikey** on Monday, December 3, 2012 at 10:22pm.

4x^2-4x+21=0

2)Find the standard form of the complex number.

8(cos pi/2 + i sin pi/2)

Thanks everyone!

- trigonometry -
**Reiny**, Monday, December 3, 2012 at 10:39pmx = (4 ± √(16 - 16(21)) )/8

= (4 ± √-320)/8

= (4 ± 8√-5)/8

= 1/2 ± i√5

x = 1/2 + i√5 or x = 1/2 - i√5

2)

8(cos π/2 + i sin π/2)

= 8(√2/2 + i √2/2)

= 4√2 + i (4√2)

**Related Questions**

math - 1)Which values of x are in the solution set y=3x-1 y=x^2-5x+6 2)6ab (...

Math - Write the slope-intercept form of an equation of the line that passes ...

Algebra II - Write y=x^2+4x-1 in vertex form. y=x^2+4x-1 y=(x^2+4x+8)-1-8 y=(x+2...

College algebra - Find the standard form of the equation of the hyperbola with ...

Math - Explain how to solve? Which equation below shows the equation y = – 1/4x...

Algebra - How do I factor out: 21 - 4x - x^2 x^2 + 4x - 21 = 0 this is of the ...

Calculus - Let h(x)= x^3 + 4x -2. Let g(x) represent the inverse of h(x). Find g...

math - solve algebraically and check y=8x+3 y=-4x-21 8x+3=-4x-21 +4x +4x 12x+3=-...

Algebra - What is 2x=7? Is it a standard form, or slope-intercept form, or not a...

math/trigonometry - solve this equation by completing the square. x^2+4x-21=0