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contoh soal integral substitusi yang melibatkan akar (√) lengkap dengan langkah penyelesaian.

Contoh Soal 1

Hitunglah:4x+1dx\int \sqrt{4x+1} \, dx∫4x+1​dx

Penyelesaian (Substitusi)

Misal:u=4x+1u = 4x+1u=4x+1 du=4dxdx=14dudu = 4\, dx \quad \Rightarrow \quad dx = \frac{1}{4} dudu=4dx⇒dx=41​du

Maka:4x+1dx=u14du\int \sqrt{4x+1}\, dx = \int \sqrt{u} \cdot \frac{1}{4}\, du∫4x+1​dx=∫u​⋅41​du =14u1/2du= \frac{1}{4} \int u^{1/2}\, du=41​∫u1/2du =1423u3/2+C= \frac{1}{4} \cdot \frac{2}{3}u^{3/2} + C=41​⋅32​u3/2+C =16(4x+1)3/2+C= \frac{1}{6}(4x+1)^{3/2} + C=61​(4x+1)3/2+C

Jawaban:16(4x+1)3/2+C\boxed{\frac{1}{6}(4x+1)^{3/2} + C}61​(4x+1)3/2+C​

Baca juga:Contoh Soal Fisika Parabola: Rumus, Konsep, dan Pembahasan Lengk

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Contoh Soal 2

Hitunglah:xx2+9dx\int \frac{x}{\sqrt{x^2+9}}\, dx∫x2+9​x​dx

Penyelesaian

Substitusi:u=x2+9u = x^2 + 9u=x2+9 du=2xdxxdx=12dudu = 2x\, dx \Rightarrow x\, dx = \frac{1}{2} dudu=2xdx⇒xdx=21​du

Maka:xx2+9dx=1u12du\int \frac{x}{\sqrt{x^2+9}}\, dx = \int \frac{1}{\sqrt{u}} \cdot \frac{1}{2}du∫x2+9​x​dx=∫u​1​⋅21​du =12u1/2du= \frac{1}{2}\int u^{-1/2}\, du=21​∫u−1/2du =122u1/2+C= \frac{1}{2} \cdot 2u^{1/2} + C=21​⋅2u1/2+C =x2+9+C= \sqrt{x^2 + 9} + C=x2+9​+C

Jawaban:x2+9+C\boxed{\sqrt{x^2+9} + C}x2+9​+C​

Contoh Soal 3

Hitunglah:x5x22dx\int x\sqrt{5x^2 – 2}\, dx∫x5x2−2​dx

Penyelesaian

Substitusi:u=5x22u = 5x^2 – 2u=5×2−2 du=10xdxxdx=110dudu = 10x\, dx \quad \Rightarrow \quad x\, dx = \frac{1}{10}dudu=10xdx⇒xdx=101​du

Maka:x5x22dx=u110du\int x\sqrt{5x^2 – 2}\, dx = \int \sqrt{u} \cdot \frac{1}{10}\, du∫x5x2−2​dx=∫u​⋅101​du =110u1/2du= \frac{1}{10}\int u^{1/2}\, du=101​∫u1/2du =11023u3/2+C= \frac{1}{10} \cdot \frac{2}{3}u^{3/2} + C=101​⋅32​u3/2+C =115(5x22)3/2+C= \frac{1}{15}(5x^2 – 2)^{3/2} + C=151​(5×2−2)3/2+C

Jawaban:115(5x22)3/2+C\boxed{\frac{1}{15}(5x^2 – 2)^{3/2} + C}151​(5×2−2)3/2+C​

Baca juga :FEB Universitas Teknokrat Indonesia Gelar Kuliah Umum Ekonomi Mikro Bahas Peran Pemerintah dalam Penyediaan Barang Publik

Contoh Soal 4

Hitunglah:dx32x\int \frac{dx}{\sqrt{3 – 2x}}∫3−2x​dx​

Penyelesaian

Substitusi:u=32xu = 3 – 2xu=3−2x du=2dxdx=12dudu = -2 dx \Rightarrow dx = -\frac{1}{2} dudu=−2dx⇒dx=−21​du dx32x=12u1/2du\int \frac{dx}{\sqrt{3 – 2x}} = -\frac{1}{2}\int u^{-1/2}\, du∫3−2x​dx​=−21​∫u−1/2du =122u1/2+C= -\frac{1}{2} \cdot 2u^{1/2} + C=−21​⋅2u1/2+C =32x+C= -\sqrt{3 – 2x} + C=−3−2x​+C

Penulis:loveytha

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