Вычислите приближенно: а) 5,01^2 б)7,98^2 в)2,99^3 г)корень из 24,1 д)корень из 35,98 е)ln 3 ж)1,01^20 з)0,98^20 и)2,01^10 к)1.99^10

Лебедев Дмитрий Сергеевич

Учитель математики

Проверено учителем

Для вычисления значений используется формула линейного приближения через дифференциал функции: f(x0+Δx)f(x0)+f(x0)Δxf of open paren x sub 0 plus delta x close paren is approximately equal to f of open paren x sub 0 close paren plus f prime of open paren x sub 0 close paren delta x. Приблизительные значения: а) 25,1, б) 63,68, в) 26,73, г) 4,91, д) 5,9983, е) 1,1036, ж) 1,2, з) 0,6, и) 1075,2, к) 972,8. ️ Шаг 1: Применение формулы для степенных функций и корней Для большинства примеров используется функция f(x)=xnf of x equals x to the n-th power или f(x)=xf of x equals the square root of x end-root . Линейная аппроксимация имеет вид: (x0+Δx)nx0n+nx0n1Δxopen paren x sub 0 plus delta x close paren to the n-th power is approximately equal to x sub 0 to the n-th power plus n x sub 0 raised to the n minus 1 power delta x. а) 5,01252+250,01=25+0,1=25,15 comma 01 squared is approximately equal to 5 squared plus 2 center dot 5 center dot 0 comma 01 equals 25 plus 0 comma 1 equals 25 comma 1 б) 7,982=(80,02)282+28(-0,02)=640,32=63,687 comma 98 squared equals open paren 8 minus 0 comma 02 close paren squared is approximately equal to 8 squared plus 2 center dot 8 center dot open paren negative 0 comma 02 close paren equals 64 minus 0 comma 32 equals 63 comma 68 в) 2,993=(30,01)333+332(-0,01)=270,27=26,732 comma 99 cubed equals open paren 3 minus 0 comma 01 close paren cubed is approximately equal to 3 cubed plus 3 center dot 3 squared center dot open paren negative 0 comma 01 close paren equals 27 minus 0 comma 27 equals 26 comma 73 г) 24,1=250,95+1225(-0,9)=50,09=4,91the square root of 24 comma 1 end-root equals the square root of 25 minus 0 comma 9 end-root is approximately equal to 5 plus the fraction with numerator 1 and denominator 2 the square root of 25 end-root end-fraction center dot open paren negative 0 comma 9 close paren equals 5 minus 0 comma 09 equals 4 comma 91 д) 35,98=360,026+1236(-0,02)=60,0165,9983the square root of 35 comma 98 end-root equals the square root of 36 minus 0 comma 02 end-root is approximately equal to 6 plus the fraction with numerator 1 and denominator 2 the square root of 36 end-root end-fraction center dot open paren negative 0 comma 02 close paren equals 6 minus the fraction with numerator 0 comma 01 and denominator 6 end-fraction is approximately equal to 5 comma 9983 ️ Шаг 2: Вычисление логарифма и высоких степеней Для ln3l n 3 выберем точку x0=e2,7182x sub 0 equals e is approximately equal to 2 comma 7182. Тогда Δx=3e0,2818delta x equals 3 minus e is approximately equal to 0 comma 2818. е) ln3lne+1e(3e)=1+0,28182,71821,1036l n 3 is approximately equal to l n e plus 1 over e end-fraction open paren 3 minus e close paren equals 1 plus the fraction with numerator 0 comma 2818 and denominator 2 comma 7182 end-fraction is approximately equal to 1 comma 1036 Для степеней (1+α)n1+nαopen paren 1 plus alpha close paren to the n-th power is approximately equal to 1 plus n alpha: ж) 1,01201+200,01=1,21 comma 01 to the 20th power is approximately equal to 1 plus 20 center dot 0 comma 01 equals 1 comma 2 з) 0,9820=(10,02)201200,02=0,60 comma 98 to the 20th power equals open paren 1 minus 0 comma 02 close paren to the 20th power is approximately equal to 1 minus 20 center dot 0 comma 02 equals 0 comma 6 Для 2,01102 comma 01 to the tenth power и 1,99101 comma 99 to the tenth power используем x0=2,Δx=±0,01x sub 0 equals 2 comma delta x equals plus or minus 0 comma 01 и производную f(x)=10x9f prime of x equals 10 x to the nineth power: и) 2,0110210+10290,01=1024+51,2=1075,22 comma 01 to the tenth power is approximately equal to 2 to the tenth power plus 10 center dot 2 to the nineth power center dot 0 comma 01 equals 1024 plus 51 comma 2 equals 1075 comma 2 к) 1,991021010290,01=102451,2=972,81 comma 99 to the tenth power is approximately equal to 2 to the tenth power minus 10 center dot 2 to the nineth power center dot 0 comma 01 equals 1024 minus 51 comma 2 equals 972 comma 8 Ответ: а) 25,1 б) 63,68 в) 26,73 г) 4,91 д) 5,9983 е) 1,1036 ж) 1,2 з) 0,6 и) 1075,2 к) 972,8 Нужно ли вам вычисление погрешности для этих приближений или использование ряда Тейлора для большей точности?

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