Tilly Report post Posted September 22, 2008 could any of you maths magicians please help with the following and hopefully explain to me how to come to the answer. Find the inverse of the following functions 3x 2x +5 7(x - 6) x/2 = 7 Cheers Tilly Quote Share this post Link to post Share on other sites
Canopus Report post Posted September 22, 2008 If a function outputs B with A as its input, then the inverse of that function outputs A with B as its input. For example: if f(x)=3x then its inverse is x/3 if f(x)=2x+5 then its inverse is (x-5)/2 You should be able to do the rest. Quote Share this post Link to post Share on other sites
Tilly Report post Posted September 22, 2008 Thanks so much Canopus. One very relieved dd and one thankful mum You're a star Tilly Quote Share this post Link to post Share on other sites
warrenpenalver Report post Posted September 22, 2008 Been a long time since i done algebra!! Quote Share this post Link to post Share on other sites
Stella63 Report post Posted September 22, 2008 That doesn't make any sense to me at all!!! I am always interested in how people work maths out but I rarely get it! My dad is a genius at maths and used to get so cross with me because I didn't get it when I was at school and now, working at a secondary school I still really struggle with a lot of the concepts (sometimes that helps the kids as if I don't understand I can tell the teacher and it can then be explained in a different way - I remember when I was at school I was made to made to feel so small for putting my hand up and saying I didn't understand - give me English lessons anyday!!! Stella x Quote Share this post Link to post Share on other sites
Mumble Report post Posted September 22, 2008 Find the inverse of the following functions 3x 2x +5 7(x - 6) x/2 = 7 As Canopus says - it's asking, "what do you need to do to reverse the result (i.e. get back where you started)"? So the inverse of adding 5 is to take-away 5, the inverse of multiplying by 3 is to divide by 3 etc. When you/son have done them, you can check by putting any number though the function and then working through your inverse and you will get back to the number you started with if it is correct... Quote Share this post Link to post Share on other sites
Enid Report post Posted September 22, 2008 If any of my lot dont understand the homework, I just put a note on it saying so! <'> Enid Quote Share this post Link to post Share on other sites
Stella63 Report post Posted September 23, 2008 Mumble - that made sense!!!! Stella x Quote Share this post Link to post Share on other sites
Mumble Report post Posted September 23, 2008 Mumble - that made sense!!!! Don't sound so shocked!! :lol: Maths is really logical (Mathematicians on the other hand... ) Quote Share this post Link to post Share on other sites