问题6.在以下每个中,确定有理数a和b:
(一世)
(ii)
(iii)
(iv)
(v)
(六)
解决方案:
(i) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a = 2, b = 1
(ii) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a = 3, b = 2
(iii) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a =, b =
(iv) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a = -1, b = 1
(v) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a =, b =
(vi) We know that rationalisation factor for. We will multiply numerator and denominator of the given expression, to get
On equating rational and irrational terms, we get
Hence, we get a =, b =
问题7。 ,找到的价值
解决方案:
We know that. We have to find the value of
As
Therefore,
We know that rationalization factor for. We will multiply numerator and denominator of the given expression
to get,
Putting the value of , we get
Hence the value of the given expression is 52.
问题8。 。找到的价值
解决方案:
We know that . We have to find the value of
Therefore,
We know that rationalization factor for .
We will multiply numerator and denominator of the given expression
to get,
Putting the value of
We get,
Hence the given expression is simplified to 34.
问题9.找到价值 ,鉴于
解决方案:
We know that for rationalization factor we will multiply denominator and numerator of the given expression
to get,
Putting the values of
we get,
Hence, value of the given expression is 11.904.
问题10.找出以下每个值的正确到小数点后三位,即
(一世)
(ii)
解决方案:
(i) We know that rationalization factor for
We will multiply numerator and denominator of the given expression
to get
Putting the values of
We get
Hence, the given expression is simplified to 0.102.
(ii) We know that rationalization factor for
We will multiply numerator and denominator of the given expression
to get
Putting the values of
We get
Hence, the given expression is simplified to 14.071.
问题11。 ,找到的价值
解决方案:
We have,
It can be simplified as
On squaring both sides, we get
The given equation can be rewritten as
Therefore, we have
Hence, the value of given expression is 10.