-10. J HODUCTION 1 1 



6. Determine the raluei of M for which the following eqmaliooe ahtll 

 have equal rooU: 



,l43,) + 7(3 + 2)r 

 r-2ti.3.-9x+10; 

 lx + (l+)x + 1 = 0; (4) x + (x + ). 



7 If in the equation 2<ur(x+ *c) + (i* - 2)c* = 0, x braal,tbow 

 that U not greater, In Absolute value, ih.i 



a If x i* n-al in the equation ^ * - = a f tbow that a U not 

 gmater than 1, nor leu than - A. 



9 For what raluei of cwili the following equation* hare equal rootoT 



U+4*+c:=0; (2) (mjr--r)=4 ; r + e)M. 



10 Solve the equation* in examples 2, 3, and 5. 



11 Solve the equation*: 



,'- 



10. Zero and infinite roots. In the following pages it will 



sometimes be necessary to know th<> com lit inns among the 



coefficients of a quadratic equation th.it will make one or 



i of its roots zero, or the conditions that will make one 



large. In equations (/> 



9, x l and x^ i.e. the roots of ax* + bx + c 0, were 

 and it is at once seen that 



-o- 



2a 



2a 



and t 



\ - 4 ac 



JT. t 



118(1) and ( that : 



< 1 ) 1: / and b remain unchanged while c grows smaller* 



