
William W. answered 11/20/22
Math and science made easy - learn from a retired engineer
6tan−1(6x) = 32π
tan−1(6x) = (32π)/6
tan−1(6x) = (16π)/3
But tan-1(x) is a function with a range of (-π/2, π/2) so it cannot ever be 16π/3 therefore the solution DNE.
−2sin−1(8x) = (2/3)π
sin−1(8x) = -(1/3)π
Let θ = 8x then:
sin−1(θ) = -π/3
Since sin−1(θ) is defined for θ on (-1, 1) for ranges (-π/2, π/2), this must be in Q4
sin(sin−1(θ)) = sin(-π/3)
θ = -√3/2
The back-substitute to get:
8x = -√3/2
x = -√3/16
−6sin−1(4x) = (3/2)π
sin−1(4x) = -(1/4)π
sin(sin−1(4x)) = sin(-π/4)
4x = -√2/2
x = -√2/8
-2tan-1(-6x) = -4π
tan-1(-6x) = 2π
But again, tan-1(x) is a function with a range of (-π/2, π/2) so it cannot ever be 2π therefore the solution DNE.
William W.
On problems 1 & 4, remember that tan^-1 is a function with a range -pi/2 to pi/2 therefore cannot be the values 16pi/3 or 2pi11/20/22