Q4. A student tried to write the statement `if a real number is positive then its cube is positive' in mathematical notation as follows:
\[
\forall x > 0 \implies x^3 > 0
\]
Is this correct? If not, what is wrong? Hint: could you construct the above using blocks?
Construct a valid expression for this statement using blocks below.
Q5. Recall that a sequence \(f\) is nondecreasing if \( \forall n \in \mathbb{N} \;\; f(n+1) \geq f(n) \);
it is nonincreasing if \( \forall n \in \mathbb{N} \;\; f(n+1) \leq f(n) \);
it is monotonic if it is nondecreasing or nonincreasing.
A student tried to write `\(f\) is monotonic' using blocks as below.
What is wrong with this? Fix it by constructing a correct expression for `\(f\) is monotonic'.
