To create the IF function in a spreadsheet:
IF from the function list.=(income - expenses) < 10000.=(income - expenses) * 10%.=(income - expenses) * 5%.The syntax of the function is:
\[ \text{=IF((income - expenses) < 10000, (income - expenses) * 10\%, (income - expenses) * 5\%)} \]

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?