bài 2 tìm GTLN a ) D = -3 – ( 1/2x + 5 ) b) E = 5 – ( y + 3/4 )^4 06/07/2021 Bởi Julia bài 2 tìm GTLN a ) D = -3 – ( 1/2x + 5 ) b) E = 5 – ( y + 3/4 )^4
`D=-3-|1/2x+5|` Vì -|1/2x+5|≤0` `→-3-|1/2x+5|≤-3` `→D≤-3` Dấu `=` xảy ra `↔1/2x+5=0↔1/2a=-5↔x=10` Vậy `D_(max) = -3 ↔x=10` `E=5-(y+3/4)^4` Vì -(y+3/4)^4≤0` `→5-(y+3/4)^4≤5` Dấu `=` xảy ra `↔y+3/4=0↔y=-3/4` Vậy `E_(max)=5↔y=-3/4` Bình luận
`D=-3-|1/2x+5|`
Vì -|1/2x+5|≤0`
`→-3-|1/2x+5|≤-3`
`→D≤-3`
Dấu `=` xảy ra `↔1/2x+5=0↔1/2a=-5↔x=10`
Vậy `D_(max) = -3 ↔x=10`
`E=5-(y+3/4)^4`
Vì -(y+3/4)^4≤0`
`→5-(y+3/4)^4≤5`
Dấu `=` xảy ra `↔y+3/4=0↔y=-3/4`
Vậy `E_(max)=5↔y=-3/4`