-sin2 x ≤ -1
Multiply both sides by -1 and swap the sign.
sin2 x ≥ 1
The biggest possible value of sin x is 1 , and the smallest possible value of sin x is -1 .
So, the biggest possible value of sin2 x is 12 or (-1)2 , which both equal 1 .
There is no way that sin2 x can be bigger than 1 .
sin2 x is not always ≥ 1
-sin2 x is not always ≤ -1
-sin2 x ≤ -1
Multiply both sides by -1 and swap the sign.
sin2 x ≥ 1
The biggest possible value of sin x is 1 , and the smallest possible value of sin x is -1 .
So, the biggest possible value of sin2 x is 12 or (-1)2 , which both equal 1 .
There is no way that sin2 x can be bigger than 1 .
sin2 x is not always ≥ 1
-sin2 x is not always ≤ -1