In the case u posted we know only min value of ur Dad's age & not the max value
So, v can use [26 , ∞]
But here we know both min & max values of I as given in the Qs
8 Answers
like if we say that my brother is more than 4 years old, then i can also say that my brother is more than 2 years old...
But sir doesn't it mean that I can now be 4 also though v know that max value of I is 3
No it doesnt..
se my 2nd example.. like if we say that my brother is more than 4 years old, then i can also say that my brother is more than 2 years old...
Does that mean that my brother is 3 yrs old? He could be 3 yrs old.. but he may not be as well..
Like if i say my dad is older than me (I am 26) then does it mean that my dad is 27?
He will in most probability be atleast 15-25 yrs older..
Yes you can say that sin x ε [-1, 2]
there is absolutely nothing wrong in it..
infact you can say that sin x ε R (real numbers )
The important thing is that you have to understand that the range is not the same as the Codomain
[-1,1] will be the range..
while [-1,2] will be the codomain.
Thank u Sir Now it's clear
These r the little misconcepts which make us loose marks : )