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f(x) = 2x + c, g(x) = cx + 5, fg(x) = 6x + d. c and d are constants. Work out the value of d. 3 marks.

fg(x) = 2(cx+5) + c = 2cx+10+c [1 mark] fg(x) = 6x+d. fg(x) = 2cx+10+c 6x = 2cx and d = 10+c [2 marks] 3 = c and therefore d = 13 [3 marks]
HK
Answered by Heba K. • Maths tutor
22711 Views

What is the general equation for a straight graph line and what does each part represent?

Y= mX + c, 'X' is the horizontal value on the axis, the input value. The 'm' represents the gradient of the line, figured out by the change in y divided by the change in x. The 'c' value is the y intercept, ...
TW
Answered by Toby W. • Maths tutor
3513 Views

Find the range of values of x for which: x^2 + 3x + 2 < 0

If you were to factorise this quadratic to find out its roots, you would get: (x+1)(x+2) which gives us roots of -1 and -2. Remember that roots are where the graph crosses the x-axis, and are found by settin...
TN
Answered by Thomas N. • Maths tutor
6302 Views

Solve x^2+8x-5 = 0 by completing the square.

x 2 + 8x = (x + 4) 2 - 16, so x 2 + 8x - 5 = (x + 4) 2 - 16 - 5 = (x + 4) 2 - 21, so then (x + 4) 2 - 21 = 0 (x + 4) 2 = 21 -----&gt; x + 4 = √21 -------&gt; x = -4 + √21 x = -4 - √21
SJ
Answered by Shadab J. • Maths tutor
12690 Views

Find an equation of the straight line that is perpendicular to the straight line x + 3y = 7 and that passes through the point (4,9).

y = 3x - 3
VP
Answered by Vikesh P. • Maths tutor
3751 Views