rules/laws

• cos = x
• tan = sin/cos = y/x
• lim x-> 0 sinx/x = 1
• lim x->0 tan x/x = 1
• lim x->0 1-cos y / x = 0
• secant or sec = 1/cos
• lim x->0 sin a x / x = a
• cosecant or csc = 1/sin
• cotangent or cot = cos/sin
• lim x->0 sin a x/ sin b x = a/b
• lim x->0 tan a x / x = a
• lim x->0 1-cos a x / x = 0
• lim x->∞ b ^ x = ∞, if b is > 1
• lim x->-∞ b^x = 0, if b > 1
• lim x->∞ b^x = 0, if 0<b<1
• lim x->-∞ b^x = ∞ , if 0<b<1
• lim x->∞ e^x = ∞
• lim x->-∞ e^x = 0
• lim x->∞ e^-x = 0
• lim x->-∞ e^-x = ∞
• lim x->0 (1+x)^1/x = e
• lim x->0 e^x - 1/x = 1