It's a misprint, you can find this question in NCERT examples ig. It should be -4 instead.
Why -4 it should be open bracket -5
Sorry, I was mistaken. Have a look at this btw, https://math.stackexchange.com/questions/1706/does-set-mathbbr-include-zero
Bro I m sure it does not include 0 in R+ ,its taught in my coaching
Yup the same question came in our preboards and i raised the same doubt but school teachers said include 0 in R⁺
I guess boards aren't like jee....bass ans nikalna hai kisi bhi tarah chahe sahi ho ya nahi