sig.fig 是什麼意思
2007-02-02 14:49:39 · 3 個解答 · 發問者 v 1 in 科學 ➔ 數學
有效數字significant figure的簡寫
為了簡化答案
就可以用sig.fig
考會考最常用係3sig.fig
2007-02-02 14:57:39 · answer #1 · answered by ? 3 · 0⤊ 0⤋
The short form of 'significant figures', in doing homework or exams, if your answer is not exact, you should round off the answer to 3 significant figures
in writing, it is
for example:
x = 7.33 (3 sig. fig.) means x is rounded to 7.33 with 3 significant figures
2007-02-03 04:58:30 · answer #2 · answered by Xero 3 · 0⤊ 0⤋
其實sig.fig.係用黎計數用ge,sig.fig越多,個數就越準,sig.fig.通常都用係一d除唔盡ge數到ge(例如:0.3861973645........),咁當我地唔可以寫曬d小數位,咁sig.fig.就有用啦。其實sig.fig.只係係d數到,拿到某一個位,或係某一個準確度咁啦。
例子一:11111,要拿 3sig.fig ,就係拿頭個3個位,就變成11100啦~
例子二:67890,拿2sig.fig.,就會變左68000
**唔要個d位要補番個0呀,仲有要跟4捨5入ge規則(好似例子二咁)~~
有一點要記住ge就係,當要拿sig.fig.個數係小數ge話,咁樣一開始個幾個0就唔可以計入要拿個d sig.fig. 入面ga,直到有一個唔係0ge數,先可以開始計,不過如果一個數係由一d唔係0ge數開始ge話,咁之後個d0就計ge。 (唔明ge話睇睇例子呀)
例子三:0.12345,拿3sig.fig.,首先,開始個數係0,我地唔可以計ga,就由第二個位,即係個1字開始,數三個位,個數就變左 0.123啦,因為係小數,所以之後本來要補0ge地方就唔使要0啦
例子四:3.0123,拿3sig.fig,因為係由3開始,唔係0,咁就可以由3開始數,咁就變成3.01啦
咁nearest thousand呀,nearest ten又係咩呢?
俾個例子呀:1111111,拿nearest ten咁係點呢,首先,ten即係十位數啦,咁題目其實係要你將十位數後面ge數唔要姐,記住唔要個d位都要補番個0,亦要跟4捨5入ge規則ga,所以題目ge1111111,就變成1111110啦
俾多個例子啦,12345,拿nearest thousand,就係變左12000啦~~~(thousand係千位數)
upper limit同lower limit呢,就係你拿左sig.fig.或者nearest xxx之後,個數就會唔同左佢本身個數啦,咁你就要找出本身個數同你改左個數最多相差幾多啦,upper limit就係本身個數同你改左個數相差ge最高上限,而lower limit就係本身個數同你改左個數相差ge最低下限啦
至於點計呢,就係將你改個個位除二,再加落你改左個數到,就係upper limit啦,咁減落你改左個數到,就係lower limit啦~~
example:15000(correct to 2 sig.fig),咁你改個位就係千位啦,咁你就將1000除二,就係500,upper limit就係15000+500=15500,lower limit就係15000-500=14500
1)850 3.sig.fig upper limit=850.5 lower limit=849.5
呢條改左ge係個位,將1除2,就係0.5,做一做加減數,就計到
2)210 nearest ten upper limit=215 lower limit=205
3)0.52 2.sig.fig upper limit=0.525 lower limit=0.515
4)210 nearest ten upper limit=215 lower limit=205
我好長氣,不過希望幫到你啦,仲有,解釋我唔係好記得,唔一定準,不過答案就岩ge~~~
2007-02-02 14:53:29 · answer #3 · answered by ? 7 · 0⤊ 0⤋