Sunday

April 20, 2014

April 20, 2014

Posted by **shreya** on Monday, May 30, 2011 at 6:24am.

a. 2x^2-x-1

b.x^2-2x-3=0

c.2x^2-5x-3=0

d. 2x^3-7x^2+2x+3=0

- maths -
**Reiny**, Monday, May 30, 2011 at 8:45amsinA+cosA=1/5

square both sides

sin^2A + 2sinAcosA + cos^2A = 1/25

2sinAcosA = 1/25 - 1 = -24/25

sin 2A = -24/25

setting my calculator to radians

2A = 4.4286 or 2A = 4.9962

A/2 = 1.10715 or A/2 = 1.249

so tan A/2 = 3.99999 or tan A/2 = 3

or tan A/2 = 0

clearly 0 does not work as a zero for any of the given equations, (they all have a constant)

tan A/2 = 3 does work in equation b)

which would factor to (x-3)(x+1) = 0 to get a root of 3

3 is also a root of c) and d) since they both factor containing a factor of (x-3)

( I know I should have been able to get tan A/2 = 3 without relying on my calculator,

**Related Questions**

Math33333 - Please help me! Problem: x+2 x-3 _________ - _________ 2x^2+5x+2 2x^...

Rational Expression - (x+1/2x-1 - x-1/2x+1) * (2x-1/x - 2x-1/x^2) (x+1/2x-1 - x-...

TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...

bobPursley2...the other one - Problem 2: (x+2)/(2x^2+5x+2) - (x-3)/(2x^2-5x-3) ...

TO KIM - can you help me with this |2x - 3|^2 - 6|2x - 3| + 5=0 I know you are ...

Math - Please show the solutions! 1.) x+y-2(2x-3y) 2.) x+y/2 - 3x-y/4 + x-5y/8 3...

alegebra - 1. What is the factored form of 4x 2 + 12x + 5? (1 point) (2x + 4)(2x...

Intermediate Algebra - Am I going in the right track? 8x -1/x + 5x - 3/2x = 16x^...

Math(Please check my work.) - (2x-3)(x^2+5x-3)=2x+10x^2-15x+9 *Is this correct...

Math - Null factor law and factoriising: 2x^2+7x=0 X(2x+7)=0 X=0 or 2x+7=0. ( ...