Class - VIII - Maths
Find Square Roots (Page 4/10)
(Contiued from page 3 )
Question Type - 4 -
181sq-180sq= ?
Answer - 4-
In this type of question remember
(N
2)-(M
2)=(N+M)*(N-M)
.
Therefore
181
2-180
2 =
(181+180) * (181-180)
= (181+180)*(1) = 361 Therefore if N=M+1 then (N
2)-(M
2)=(N+M)
Question Type - 5 -
Which of following triplets are Pythagorean.
(2,3,4); (3,4,5); (6,7,8), (10,24,26)
Answer - 5-
A Pythagorean triplets is when
X2+Y2=Z2 i.e. X*X+Y*Y=Z*Z
(2,3,4); 2*2+3*3 = 13 and not equal to 4*4 (i.e. 16)
(3,4,5) ; 3*3+4*4=25=5*5 therefore
(3,4,5) is Pythagorean triplets
(7,8,9) ; 7*7+8*8= 113 and not equal to 9*9 (i.e. 81)
(10,24,26) ; 10*10+24*24 = 676 = 26*26 therefore
(10,24,26) is Pythagorean triplets
(Cont..... to page 5 )
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