I like c)
I really need help with this question..
Which of the following are true for all real numbers a,b>0? For those that are not always true, give specific values of a,b>0 where they fail
(a) 1/a +1/b = 1/(a+b)
(b) 1/(a) + b = (1+b)/a
(c) 1/a +1/b = (a+b)/ab
To show that a statement doesn't hold, all you need to do is find a counterexample to what the statement asserts. For instance if you want to disprove
,
you can just notice that
.
Just try a couple of values and you'll soon find a pair which violates the assertion.