You can use the unit circle or your calc for this (don't forget to put it in radians!). I will use the unit circle to explain.
Tangent on the unit circle is on the xy lines themselves. tan (π/2) would be on the positive y axis. Remember that tan∅ is <em>sin∅/cos∅</em> and that the unit circle's radius is always one. If that is the case, the coordinate for tan (π/2) would be (0, 1). If cos is always x and sin is always y, you plug it in for tan∅. The fraction 1/0 is undefined, since you can't divide anything by 0. Therefore, tan (π/2) is undefined.
• Imagine we are using these two points to draw a triangle where new point E is a right angle with coordinates (-1, -9) • FE = 5 • EC = 4 • FE^2 + EC^2 = FC^2 • (25) + (16) = 41 = FC^2 • FC = square root(41)
