Quizzes & Puzzles6 mins ago
Maths solving simultaneous equations using graphs
here is the question:
1.a)draw the graph of x^2 + y^2 = 25 and y = x + 1 on the same grid.
b) Use the graph to solve simultaneously the two equations.
is it allowed to plot the graph (after rearranging the formula) y = square root of 2 - x^2 (there isnt a square root key on the keyboard lol)
please help asap
thanx
xx
Answers
No best answer has yet been selected by *mystical*. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.Another approach is to get the 2 equations looking similar and then add or subtract them from each other. I'm sure there's a technical term for this but :
x� + y� = 25 or y� = 25 - x�
and
y=x+1 or y� = (x+1)�
start to look similar, in that you've isolated the y� part.
y� = x� + 2x +1 (which, if you introduce the first equation, is equal to 25-x� )
25 - x� = x� + 2x + 1
0 = 2x� + 2x - 24 (divide by 2)
gives (x+3)(x-4) so x=3 (which makes y=4)
and x= -4 (and thus y=-3)
When you have a graph with axes x & y you cannot 'plot' y� as such so you need to rearrange it into the form y = ... so that for every value of x you put into the equation you get the corresponding value for y, with each pair x,y being a point on the graph.
You can also place as many equations as you find practical on one graph.
Related Questions
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.