Skip to main content

[Community Question] Calculus: Obtaining a step function given a condition

One of our user asked:

Find a step function s such that $$\int_{0}^{2} s(x) dx=5 \quad \int_{0}^{5} s(x) dx=2$$ The given answer is $$s(x)=\dfrac{5}{2} \quad \text{if} \quad 0 \leq x < 2$$

$$s(x)=-1 \quad \text{if} \quad -2 \leq x \leq 5$$

I don't understand how does one arrive to this solution.. even graphically trying to understand it I didn't come to a solution. Can someone please help me figure out how?


Comments

Popular posts from this blog

[Community Question] Linear-algebra: non-negative matrix satisfying two conditions

One of our user asked: A real matrix $B$ is called non-negative if every entry is non-negative. We will denote this by $B\ge 0$ . I want to find a non-negative matrix $B$ satisfying the following two conditions: (1) $(I-B)^{-1}$ exists but not non-negative. Here $I$ is the identity matrix. (2) There is a non-zero and non-negative vector $\vec{d}$ such that $(I-B)^{-1}\vec{d}\ge 0$ . I tried all the $2\times 2$ matrices, but it did not work. I conjecture that such a $B$ does not exist, but don't know how to prove it.

Order of elements of the Prüfer groups $\mathbb{Z}(p^{\infty})$

Let $\mathbb{Z}(p^{\infty})$ be defined by $\mathbb{Z}(p^{\infty}) = \{ \overline{a/b} \in \mathbb{Q}/ \mathbb{Z} / a,b \in \mathbb{Z}, b=p^i$ $ with$ $ i \in \mathbb{N} \}$ , I wish show that any element in $\mathbb{Z}(p^{\infty})$ has order $p^n$ with $n \in \mathbb{N}$ . i try several ways but I have not been successful, some help ?? thank you