Posted by shreya on Monday, May 30, 2011 at 6:24am.
if sinA+cosA=1/5, then a value of tanA/2 satisfies which of the equation?
- maths - Reiny, Monday, May 30, 2011 at 8:45am
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,
Answer This Question
More Related Questions
- Maths - Hi, can someone give me the answer to this question: secA-tanA=1/4. Find...
- maths(trigonometry) - prove that sinA-cosA+1/sinA+cosA-1=1/secA-tanA
- trig - Establish the following identity: CosA/1-TanA + SinA/1-CotA = CosA-SinA
- further mathematics - Let P=(cosA sinA) (sinA cosA) Q=(cosB sinA) (sinB cosA) ...
- trig - if 5cos A plus 3=0 and 180<A<360..without using a calculator and ...
- Trigonometry - If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/...
- Maths - Prove: 1+(TanA/SinB)^2/1+(TanA/SinC)^2 = 1+(SinA/TanB)^2/1+(SinA/TanC)^...
- Maths, Divine International Public School - If 15Cot=8, find (1+SinA)(1-SinA)/(1...
- mathematics trignometry - prove that the following are identity 1. (cotA+cosecA-...
- Trigonometric Identities - Verify/prove the following: (sinA+tanA)/(1+secA) = ...