y=x^2-8x+15/x^2-x-6=[(x-3)(x-5)]/[(x-3)(x+2)]
=(x-5)/(x+2)
=(x+2-7)/(x+2)
=1-7/(x+2)
x≠3,x≠-2.
∵7/(x+2)≠0,∴1-7/(x+2)
≠1
∵x≠3,∴1-7/(x+2)
≠-2/5
函数y=x^2-8x+15/x^2-x-6的值域是{y|y≠-2/5且y≠1}
看不懂再问..望采纳!!!
先将
y=x²-x-6分之x²-8x+15因式分解,要不等等我把过程打成图片发上来