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-x²+2x+3
=-(x²-2x+1)+4
=-(x-1)²+4
âµ -x²+2x+3å¨(--âï¼1]为å¢å½æ°ï¼å¨[1ï¼+â)为
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å¤åå½æ°y=3^(-x²+2x+3) ï¼
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解ï¼
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â´å¤åå½æ°y=3^(-x²+2x+3) ç
å®ä¹å为Rã
y = 3^(-x²+2x+3)
= 3^[-(x²-2x+1)+4]
= 3^[-(x-1)²+4]
⤠3^4 = 81(åºæ°ä¸º3ï¼æ¯å¢å½æ°)
â´
å¼å为:(0ï¼81]
y = 3^(-x²+2x+3)
= 3^[-(x-1)²+4]
âµ -(x-1)²+4 å¨(--âï¼1]为å¢å½æ°ï¼å¨[1ï¼+â)为åå½æ°ï¼
â´ y = 3^(-x²+2x+3) å¨(--âï¼1]åè°éå¢ï¼å¨[1ï¼+â)åè°éåã
â´ y = 3^(-x²+2x+3)åè°éå¢åºé´æ¯(-âï¼1]ï¼åè°éååºé´æ¯[1ï¼+â)ã
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