Needs help urgently: Maths P1

[Amy Bloom]

Can anyone outta here clear my doubts:
Why is this so?
-1<sinx<1?
When you have to find the range of this function: 3+2sin^2x???

and

If tan^2a - sin^2a = tan^2asin^2a,
Why tan a > sin a when a is 90 degrees?

 

[bamteck]

I think for the minimum, you'll have to 0 not -1 coz sin²x is 'squared'

Note : This is only done when you have sin²x or cos²x because any negative number squared, you'll get it positive !

 

[Amy Bloom]

I think for the minimum, you'll have to 0 not -1 coz sin²x is 'squared'

Note : This is only done when you have sin²x or cos²x because any negative number squared, you'll get it positive !

Okay i'll bear that in mind.