Please help with 3 pre-calc questions math homework?

dont understand how to solve these 3 questions from my homework, please help?1. Use the given values to evaluate(if possible) the remaining trigonomet

don't understand how to solve these 3 questions from my homework, please help?

1. Use the given values to evaluate(if possible) the remaining trigonometric functions. Given: sin theta=2/sqrt 5 and cos theta=1/sqrt 5.

2. Verify the identity (1-2 sin^2 theta)/(sin theta cos theta)=cos theta-tan theta

3. Solve the equation sin theta cos theta=-1/2 on the interval [0,2pi).

or:don't understand how to solve these 3 questions from my homework, please help?1. Use the given values to evaluate(if possible) the remaining trigonometric functions. Given: sin theta=2/sqrt 5 and cos theta=1/sqrt 5.2. Verify the identity (1-2 sin^2 theta)/(sin theta cos theta)=cos theta-tan theta3. Solve the equation sin theta cos theta=-1/2 on the interval [0,2pi).

or:Im taking theta as x as theta is too long to type Sinx = 2/root(5)Cosx=1/root(5)Tanx = sinx /cosx = 2 Secx= 1/cosx= root(5)Cosecx = 1/sinx = root5/2 Cotx= 1/tanx = 1/2 There goes the first one Ur second q is wrong U get the ans as cot x-tanx not cosx-tanx 1-2sin^2x)/sinx cosxCos^2x+sin^2x -2sin^2X )/SINXCOSXCos^2x -sin^2x /sinxcosxDividing numerator by denominatorDivide term by term Cotx-tanxThere's the second Third im not really sure But I guess it's likee this Sinxcosx =-1/2Sin2x/2 = -1/2 (sin2x = 2sinxcosx (standard resultSin2x = -1 2x = 3pi/2(sin3pi/2 = -1 X = 3pi/4 Just check if thats the ans I hope that helped

Tags:question,