Given the equation below, what is the value of x? 3^(x)=21?
回答 (5)
2020-11-18 11:16 pm
3^x=21
=>
xln(3)=ln(21)
=>
x=ln(21)/ln(3)=?
Use your calculator to find the answer.
=>
xln(3)=ln(21)
=>
x=ln(21)/ln(3)=?
Use your calculator to find the answer.
2020-11-18 10:57 am
3^x = 21
xln(3) = ln(21)
x = ln(21)/ln(3)
x = 2.7712
xln(3) = ln(21)
x = ln(21)/ln(3)
x = 2.7712
2020-11-18 6:45 am
3^x = 21
ln(3^x) = ln21
x * ln3 = ln21
x = ln21/ln3
ln(3^x) = ln21
x * ln3 = ln21
x = ln21/ln3
2020-11-18 4:50 am
3^x = 21
If we get the log of both sides we get:
ln(3^x) = ln(21)
We can now move the exponent out of the log:
x ln(3) = ln(21)
Divide both sides by ln(3):
x = ln(21) / ln(3)
That's your exact answer. If you want a decimal approximation rounded to a few digits a calculator gives us:
x = 2.771244 (rounded to 6DP)
If we get the log of both sides we get:
ln(3^x) = ln(21)
We can now move the exponent out of the log:
x ln(3) = ln(21)
Divide both sides by ln(3):
x = ln(21) / ln(3)
That's your exact answer. If you want a decimal approximation rounded to a few digits a calculator gives us:
x = 2.771244 (rounded to 6DP)
2020-11-18 4:49 am
log3(3^x) = log3(21)
x = log3(21) = log(21)/log(3) = 1.32/0.477 = 2.77
Verify
3^2.77 = 21
x = log3(21) = log(21)/log(3) = 1.32/0.477 = 2.77
Verify
3^2.77 = 21
收錄日期: 2021-05-01 22:15:08
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