Question

find the value of c^4+d^4 if the value of c+d=3 and c^2+d^2=7
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Answer 1

Answer:

c+d=3

by squaring both sides

(c+d)^2=(3)^2

c^2+d^2+2×c×d=9

7+2cd=9

2cd=9-7

2cd=2

cd=2/2

cd=1

again,by squaring both sides

(c^2+d^2)=(7)^2

(c^2)^2+(d^2)^2+2×c^2×d^2=49

c^4+d^4+2×c×d×c×d=49

c^4+d^4+2×1×1=49

c^4+d^4+2=49

c^4+d^4=49-2

c^4+d^4=47