Determine which of the following statements is true and which is not, with giving the reasons: 1-If \( f:(R, U) \rightarrow(R, U) \) is a function such that \( \mathrm{f}(\mathrm{x})=\mathrm{b} \forall x \in R \), where U is the usual topology on R , then f is continuous, open and closed. 2-A \( A T_{0} \) - space is a topological property, but a disconnected space is not topological. 3-A \( T_{2} \)-space implies a \( T_{1} \)-space implies a \( T_{0} \)-space and the converse is true also.

How old was charlton heston in the 10 commandments?

Encuentre una base ortonormal en \( \mathrm{R}^{2} \) que incluya al vector \( v=\binom{5}{2} \).

3.20. Para \( n \in \mathbb{Z}^{+} \)se define \( f(n) \) como el número de enteros positivos \( <n \) que sc primos relativos con \( n \), por ejemplo \[ \begin{aligned} f(1)=1, \\ f(2)=1, \\ f(3)=2, \\ f(4)=2 .\end{aligned} \] 3.20.1. Calcular \( f(10), f(13), f(18), f(24) \). 3.20.2. Para \( n=12,18,19,25 \) calcule 3.20.3. Infiera una fórmula para \[ \sum_{d \mid n} f(d) . \] donde \( n \in \mathbb{Z}^{+} \). \( \sum_{d \mid n} f(d) \),

4.) What is the next (and final) step before the amendment becomes part of the "supreme law of the land?"

Decide whether the following statement is true or false. The graph of \( y=-f(x) \) is the reflection about the \( x \)-axis of the graph of \( y=f(x) \). Choose the correct answer below. False True