90 degrees

• tangent pi/2 = undefined
• cosecant pi/2 = 1
• cos pi/2 = 0
• sin pi/2 = 1
• cos 90 = 0
• sin 90 = 1
• tangent 90 = undefined
• cosecant 90 = 1
• secant 90 = undefined
• cotangent 90 = 0
• tangent pi/2 = undefined
• secant pi/2 = undefined
• cosecant pi/2 = 1
• cotangent pi/2 = 0