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trigonometry help please!!?
6 tan x - sec^2 x = 7
any help really appreciated :)
3 Answers
- ?Lv 41 decade agoFavorite Answer
6 tan x - sec^2 x = 7
6tanx - (1+tan^2x) =7
6tanx -1 -tan^2x =7
tan^2x -6tanx +8 = 0
(tanx-2)(tanx-4) = 0
tanx=2 ; tanx = 4
key angle
63.4 ; 76.0
tan positive is found in the 1st & 3rd qudrant
for tanx =2
x = 63.4, (180+63.4)=243.4
for tanx =4
x= 76, (180+76) = 256
x=63.4, 76, 243.4, 256
here i'm assuming x is between 0 & 360
- ?Lv 61 decade ago
You need to give us a little more on the range/ domain of your problem
The quadratic becomes :
tan(x) ^2 -6tan x + 8
so tan x = 4 or tan x = 2
this gives x = about 76° and 63.4° ( appriox )
now do you want it in degrees ? Radians ?? first quadrant only ? all values from 0 to 360° ? The general formula ?
add some detail, and one of us can finish this problem.
Source(s): Retired Math Teacher - 1 decade ago
replace sec^2 x by 1 + tan^2 x
and put tanx = t
solve the quadratic for t
then put tanx equal to those solutions of quadratic equation
get the desired value of x