09ME102 Unit 2 recap

Round the following number to 3 significant figures:

0.000519728

Which of the following rounds to 15 when rounded to 2 significant figures?

• 1490

• 15000

• 15.623

• 14.7

Which of these symbols represents the number set for the Integers?

• $N$

• $Z$

• $Q$

• $R$

Which of these number set(s) does 7.5 belong to?

• Natural

• Integers

• Rational

• Real

Express the following number in scientific notation (use ^ to mean 'to the power of'):

3,205,000

Write the following number in ordinary standard form:

 $6.3\ \times\ 10^{-4}$  

The diameter of Earth is approximately

12 756 000 metres.

If the Snowpiercer train makes 2.7 revolutions around the Earth each year, how many kilometres does it travel annually?

Express your answer in scientific notation correct to three significant figures.

(use ^ again and do not write the units)

 $3\left(2y^2\right)^0$  

simplifies to:

• 6

• 3

•  $6y^2$  

•  $3y$  

• 12

 $\frac{3}{\left(2x\right)^{-2}}$  is equivalent to:

•  $-\frac{3}{\left(2x\right)^2}$  

•  $6x^2$  

•  $\frac{3x^2}{2}$  

•  $12x^2$  

•  $-\frac{3x^2}{4}$  

Simplify $3\sqrt{a}\times2\sqrt{b}$  leaving your answer as a surd

Type 'root( )' for the  $\sqrt{ }$  symbol, e.g.  $3\sqrt{a}$ = 3root(a)