consider Q.no. 55 maths section 2, paper 2. I am just changing it a little.

 

Let f(x)=2+cosx.

Statement 1:For each real t, there exists a point c in the interval [t,t+2] such that f ' (c)=0.

 

Statement 2: f(t)=f(t+2).

check the following options.

a If both statements are correct and 2 is the reason of 1.

b If both are correct but 2 is not the reason of one.

c If 1 is correct but 2 is false.

d If 2 is correct and one is false.

 

Now my question is as follows.

This is a question of rolle's theorem. Undoubtedly, both 1 and 2 are correct. But my question is (which also occured to me during the exam, thus confusing me) that which the correct option be a or b.

 

For rolle's theorem to be satisfied, 2 is necessary but not the only factor. Therefore what i understand, 2 is a reason of 1, but only one of the many reasons. So what should be the answer ?

 

Also please suggest how to tackle such ambiguities in such assertion reason type questions. I find them very confusing at times.

Thanks Bipin.

Now I only want suggestions how to tackle such assertion reason questions. Compared to others, they are rarely found in books.