若a^4+b^4+a²b²=5,ab=2,求a²+b²的值?
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![若a^4+b^4+a²b²=5,ab=2,求a²+b²的值?](/uploads/image/z/1573791-15-1.jpg?t=%E8%8B%A5a%5E4%2Bb%5E4%2Ba%26%23178%3Bb%26%23178%3B%3D5%2Cab%3D2%2C%E6%B1%82a%26%23178%3B%2Bb%26%23178%3B%E7%9A%84%E5%80%BC%3F)
若a^4+b^4+a²b²=5,ab=2,求a²+b²的值?
若a^4+b^4+a²b²=5,ab=2,求a²+b²的值?
若a^4+b^4+a²b²=5,ab=2,求a²+b²的值?
(a²+b²)²
=a^4+b^4+2a²b²
=a^4+b^4+a²b²+a²+b²
=a^4+b^4+a²b²+(ab)²
=5+2²
=9
所以a²+b²=3
(a²+b²)^2=a^4+b^4+a²b²+(ab)^2=5+4=9
所以
a²+b²=3
请问"a^4+b^4"是什么?