Cho f(x) = 1=x ³ + x $x^{5}$ +x $x^{7}$ + …+x $x^{101}$ Tính f(1); f(-1) 15/10/2021 Bởi Ayla Cho f(x) = 1=x ³ + x $x^{5}$ +x $x^{7}$ + …+x $x^{101}$ Tính f(1); f(-1)
$\text { Đáp án: }$ $\text { f(1) = 1³ + 1⁵ + 1⁷ + … + 1¹⁰¹ }$ $\text { ⇒ f(1) = 1 + 1 + 1 + … + 1 }$ $\text { ⇒ f(1) = 1 . 101 }$ $\text { ⇒ f(1) = 101 }$ $\text { Vậy f(1) = 101. }$ $\text { f(–1) = (–1)³ + (–1)⁵ + (–1)⁷ + … + (–1)¹⁰¹ }$ $\text { ⇒ f(–1) = –1 + (–1) + (–1) + … + (–1) }$ $\text { ⇒ f(–1) = –1 . 101 }$ $\text { ⇒ f(–1) = –101 }$ $\text { Vậy f(–1) = –101. }$ Bình luận
$\text { Đáp án: }$
$\text { f(1) = 1³ + 1⁵ + 1⁷ + … + 1¹⁰¹ }$
$\text { ⇒ f(1) = 1 + 1 + 1 + … + 1 }$
$\text { ⇒ f(1) = 1 . 101 }$
$\text { ⇒ f(1) = 101 }$
$\text { Vậy f(1) = 101. }$
$\text { f(–1) = (–1)³ + (–1)⁵ + (–1)⁷ + … + (–1)¹⁰¹ }$
$\text { ⇒ f(–1) = –1 + (–1) + (–1) + … + (–1) }$
$\text { ⇒ f(–1) = –1 . 101 }$
$\text { ⇒ f(–1) = –101 }$
$\text { Vậy f(–1) = –101. }$