Posted by trig on Monday, November 12, 2012 at 5:16pm.
Solve tan2A  2tanA = 1 for 0º≤A≤360º.

trig  Steve, Monday, November 12, 2012 at 5:26pm
Hmmm. Sensing a missing ^ character, we have
tan^2(A)  2tanA + 1 = 0
(tanA  1)^2 = 0
tanA = 1
So, A = 45º or 225º

trig  Reiny, Monday, November 12, 2012 at 5:52pm
or taking it at face value the way it was typed
tan 2A  2tan A = 1
2tanA/(1tan^2 A)  2tanA = 1
let tanA = x for easier typing
2x/(1x^2)  2x = 1
times 1  x^2
2x  2x + 2x^3 = 1 + x^2
2x^3  x^2 + 1 = 0
by Wolfram
http://www.wolframalpha.com/input/?i=2x%5E3++x%5E2%2B1%3D0
x = .657298
tanA = .657298
A = 146.7° or A = 326.7°
both work

trig  Anonymous, Wednesday, November 14, 2012 at 3:56pm
a ladder leaning against a vertical wall make an angle 24 degrees with the wall.the foot of the ladder is 5 ft from the wall find the length of the ladder

trig  jr, Monday, April 7, 2014 at 7:41pm
You lean a ladder 6.7 m long against a wall. It makes an angle of 63 degrees with the level ground. How high up is the top of the ladder?
Answer This Question
Related Questions
 Trigonometry  Solve tan2A  2tanA = 1 for 0º≤A≤360º.
 algebra 1 help please  4) a student score is 83 and 91 on her first two quizzes...
 Trig  Let sin A = 12/13 with 90º≤A≤180º and tan B = 4/3 with 270...
 trig  Let sin A = 12/13 with 90º≤A≤180º and tan B = 4/3 with 270...
 Algebra 2  Solve. 4a2≤a+1≤3a+4 4a21≤a+11≤3a+41 4a...
 Differentials (calc)  Solve the Poisson equation ∇^2u = sin(πx) for ...
 PRE  CALCULUS  Eliminate the parameter t. Find a rectangular equation for the ...
 Math  Let sin A = 12/13 with 90º≤A≤180º and tan B = 4/3 with 270...
 Math  Solve 4cos^2A = 3cosA for 90º≤A≤180º. (Enter only the number...
 Algebra 2  Did I solve this quadratic inequality correctly? Is my work correct...
More Related Questions