Quadratic Formula & Trigonometric Equations...2

[nycmathguy]

Section 5.3

Why is arccos[(4 + sqrt{32})/8] undefined?

 

[MathLover1]

solutions are correct

now answering: Why is arccos[(4 + sqrt{32})/8] undefined? -> because solution is an imaginary number

Real domain for arccos (x ) is -1<=x<= 1
so, cos^-1((4+ sqrt(32))/8) has No Solution for x in R, for that reason is undefined for x in R

 

[nycmathguy]

solutions are correct

now answering: Why is arccos[(4 + sqrt{32})/8] undefined? -> because solution is an imaginary number

Real domain for arccos (x ) is -1<=x<= 1
so, cos^-1((4+ sqrt(32))/8) has No Solution for x in R, for that reason is undefined for x in R

Is there a math course that mixes trigonometry with imaginary numbers?