Stephanie's Reflection

SOLVING TRIG EQUATIONS

for any line m = tan alpha
m = slope , alpha = angle of inclination
For a conic: tan 2 alpha = B/A-C
if A=C then pi/4
A = coefficient of x^2, B = coefficient of xy, C = coefficient of y^2

Eg: find the value of x between 0 and 2pi for which sinx=6.
xsin-1=6
x=36.870, 143.130

2cos theta+9=7
theta=cos-17-9//3
theta=48.190
theta=131.810, 228.190

2tan theta+1=0
theta=tan -1 -1/2
theta=26.465
theta=153.435
153.435 times pi/180
theta=.853 pi