The Value of the Inverse Tan of 1. As you can see below, the inverse tan

^{-}^{1}(1) is 45° or, in radian measure, Π/4. It is helpful to think of tangent as the ratio of**sine**over**cosine**, ie: . Therefore, tan(Θ) to equal 1,**sin**(Θ) and**cos**(Θ) must have the same value.In respect to this, why is it impossible for sin to be greater than 1?

The hypotenuse in a right triangle is always

**larger than**the opposite side, so for angles**greater than**zero but less**than**90º the**sine**ratio**will**be less**than 1**. For angles outside of these limits, the**sine**ratio**can**have values from -**1**to**1**.Is inverse sine the same as 1 sin?

That's actually a logical choice, since

^{−}**is the standard way to designate an**^{1}**inverse**function. But the problem is that it makes you want to think of**sin**^{−}**(x) as**^{1}**1**/**sin**(x), even though they're not the same at all. Many calculators use**sin**^{−}**for the function name, though some use lower-case arcsin.**^{1}What is the sin of 0?

(1,

**0**) = (x, y) = (cos**0**,**sin 0**), cos**0**= 1,**sin 0**=**0**. The values of angles outside Quadrant I can be computed using reference angles, and the values of the other trigonometric functions can be computed using the reciprocal and quotient identities.