The cross method is a factorisation method used for quadratics.
Since the equation is in standard form (ax2+bx+c=0) we can factorise using the cross method.
2sec2A-3secA+1=0
To factorise, we need to find two values on the left side that multiply to 2sec2A and two values on the right side that multiply to 1 and, when cross multiplied with the left side values and added together, gives -3secA
For the left side, 2secA and secA fit the condition
The cross method is a factorisation method used for quadratics.
Since the equation is in standard form (ax2+bx+c=0) we can factorise using the cross method.
2sin2θ+7sinθcosθ+3cos2θ=0
To factorise, we need to find two values on the left side that multiply to 2sin2θ and two values on the right side that multiply to 3cos2θ and, when cross multiplied with the left side values and added together, gives 7sinθcosθ
For the left side, 2sinθ and sinθ fit the condition
2sinθ×sinθ
=
2sin2θ
For the right side, cosθ and 3cosθ fit both conditions