2.(a) Express √2 cos x - √5 sin x in the form R cos(x + α), where R > 0 and 0° < α < 90°. Give the exact value of R and the value of a correct to 3 decimal places.
[3]
(b) Hence solve the equation √2 cos 2θ - √5 sin 2θ = 1, for 0° < θ < 180°.
[4]

step-by-step explanation:

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.

this is answer of 144 cubic meters

solve systems of equations by graphing. a system of linear equations contains two or more equations e.g. y=0.5x+2 and y=x-2. the solution of such a system is the ordered pair that is a solution to both equations. to solve a system of linear equations graphically we graph both equations in the same coordinate system