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The coefficient of ax²+bx+c=0 are obtained by throwing a die find the probability of the equation has real and equal roots , real and unequal roots , not real |
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Answer» Answer: FIRST let's talk about real ROOTS. Since each of the coefficients a, b, and c can take the values from 1 to 6 Therefore,total number of equations = 6 6 6 = 216. The roots of the equation ax2 + bx + c = 0 will be real, if b2 - 4 ac 0 b2 4 ac. The favourable number of elementary events can be enumerated as under: ac a c 4ac b(so that b2 4ac) Number of ways 1 1 1 4 2,3,4,5,6 1 5 = 5 2 1,2 2,1 8 3,4,5,6 2 4 = 8 3 1,3 3,1 12 4,5,6 2 3 = 6 4 1,4,2 4,1,2 16 4,5,6 3 3 = 9 5 1,5 5,1 20 5,6 2 2 = 4 6 6,2,3 1,3,2 24 5,6 4 2 =8 7 ac is not possible 0 8 2,4 4,2 32 6 2 1 = 2 9 3 3 36 6 1 Total = 43 Since b2 4 ac and the maximum value of b2 is 36, therefore ac = 10 , 11,12 ... etc. is not possible.Therefore,we reject such values. Therefore, Total number of favourable elementary events = 43. Hence, REQUIRED probability= 43/216 Now, Real and equal ⇒b² −4ac=0 Each coefficients is an integer, So we consider the following cases b=1⇒ 41 =ac No integral value of a and c b=2⇒1=ac∴(1,1) b=3⇒ 29 =ac No integral value of a and c b=4⇒4=ac∴(1,4),(2,2),(4,1) b=5⇒ 225 =ac No integral value of a and c b=6⇒9=ac∴(3,3) Thus we have 5 favorable ways for b=2,4,6 Total number of equation is 6.6.6=216 Therefore required probability is 5/216 Now Real and Unequal.. its simple Real - Equal So 43/216 - 5 /216 = 38/216 For not real, subtract total possibilities from real ones. 216-43 = 173/216 I have tried my best and hope it's correct.. Follow and mark brainliest please..
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