Limit Question

[Power of One]

I don't understand this problem. Can someone please help me?

Problem:

Lim [ cos(?+?x) +1 ] / ?x
?x -> 0

Hint: cos(x+y)=cosx cosy-sinx siny

My attempt:

[cos? cos?x + sin? sin?x + 1]/ ?x

[-1 cos?x + 0 sin?x +1 ]/ ?x

(-cos?x + 1)/ ?x

I don't know what to do from here. I want to get rid of ?x from the denominator, but I don't know how to. Can someone please help me?

 

[Deleted member 4993]

I don't understand this problem. Can someone please help me?

Problem:

Lim [ cos(?+?x) +1 ] / ?x
?x -> 0

Hint: cos(x+y)=cosx cosy-sinx siny

My attempt:

[cos? cos?x + sin? sin?x + 1]/ ?x

[-1 cos?x + 0 sin?x +1 ]/ ?x

(-cos?x + 1)/ ?x

I don't know what to do from here. I want to get rid of ?x from the denominator, but I don't know how to. Can someone please help me?

Have you been taught L'Hospital's Theorem?