# Pls help me on this during the rainy season

Philippines
July 7, 2007 11:51pm CST
the southwest of Metro Manila received heavy rain. The water level of a flooded area was 75 cm deep, and dropped by 3 cm/hr after the heavy rain stopped. Let x represent the number of hours and f(x) represent the water's height. a.) Form the equation in functional notation. b.) Set up the table of values for x and f(x) c.) Why is it not necessary to choose negative values for x? please help me answer this...thanks!
1 person likes this
2 responses
@migenKC (792)
• Philippines
8 Jul 07
i cant remember how to make an equation in functional notation buy hope i can help you on this... on your number 3 question... its not necessary since x represents time.. there is no such thing as negative one hour... a time doesnt go back but continues to go forward... did you get it? on your 2nd question... its hard to expalin it to you coz i need to draw lines... hmp... what can i do? i guess its somethin like this...(since you're a Filipino.. let me expalain it to you on tagalog... is it ok? mag lagay ka ng dalawang rows... sa left side naga represent ng x values... while sa right side... naga represent ng f(x)..sa gitna isang line... bale ibig sabihin if 0 ang x... ang equivalent nya sa f(x) ay 75 since di pa naman nababwasan ang water... then... if 1 ang x... ang equivalent nya sa f(x) ay 72 since nabawasan na ng 3cm ang water... then.. if 2 ang x... ang equivalent nya sa f(x) ay 69 since nabawasan na ulit ng 3cm.... and so on.. every after an hour nababawasan ang water ng 3 cm... ayun... ahihi... di ko lang mabigay ang equation... nalimutan ko na kasi pano mag form... ang tagal ko na kasi na lesson.. anong year ka na? ahihi.. nag tagalog na ako... :)
@migenKC (792)
• Philippines
8 Jul 07
ah,, tama... parang ganito yung equation... di ko lang sure kung tama ang pagka arrange ha.. f(x)= 75-[x(3)] ahihi...
1 person likes this
@migenKC (792)
• Philippines
8 Jul 07
or pede ding... f(x)= 75-3x feel ko mas tama to kaysa sa dun sa isa... ahihi
1 person likes this
• Philippines
9 Jul 07
salamat po talaga!
@beauty_ph (2751)
• Philippines
10 Jul 07
the southwest of Metro Manila received heavy rain. The water level of a flooded area was 75 cm deep, and dropped by 3 cm/hr after the heavy rain stopped. Let x represent the number of hours and f(x) represent the water's height. I know how to answer this: a.) Form the equation in functional notation. f(x)=75-3x b.) Set up the table of values for x and f(x) f(x) x 75 0 72 1 69 2 c.) Why is it not necessary to choose negative values for x? Time is never negative. Also if choose a negative value for x, instead of seeing the depth of water to drop it goes up which makes the statement false. Do you think I get it right?