What is the limit as x approaches 0 of tanx/x?

2 Answers
Jun 12, 2018

1

Explanation:

lim_(x->0)tanx/x

graph{(tanx)/x [-20.27, 20.28, -10.14, 10.13]}

From the graph, you can see that as x->0, tanx/x approaches 1

Jun 12, 2018

Remember the famous limit:

lim_(x->0) sinx/x = 1

Now, let's look at our problem and manipulate it a bit:

lim_(x->0) tanx/x

= lim_(x->0) (sinx "/" cosx)/x

= lim_(x->0) ((sinx/x)) / (cosx)

= lim_(x->0) (sinx/x) * (1/cosx)

Remember that the limit of a product is the product of the limits, if both limits are defined.

= (lim_(x->0)sinx/x) * (lim_(x->0)1/cosx)

= 1 * 1/cos0

= 1

Final Answer