第一題：可以用正弦定理得：sinA /a=sinB /b
所以得sinA=1/2,所以angle A=30度
第二題：由韋達(dá)定理得：方程根=[（-2i±根號(hào)下（4i²+16）]/2=-i±根號(hào)下3
所以選e
希望答案能滿意.
in triangle abc a=12 b=16 and sinB=2/3 what is the measure of angle A in degrees
in triangle abc a=12 b=16 and sinB=2/3 what is the measure of angle A in degrees
還有：
the equation x^2+2ix-4=0 has as its toot
a根號(hào)下5-1,-根號(hào)下5-1
b根號(hào)下5-i,根號(hào)下5+i
c根號(hào)下3-i,根號(hào)下5+i
d根號(hào)下3-i,根號(hào)下3+i
e根號(hào)下3-1,-根號(hào)下3-i
還有：
the equation x^2+2ix-4=0 has as its toot
a根號(hào)下5-1,-根號(hào)下5-1
b根號(hào)下5-i,根號(hào)下5+i
c根號(hào)下3-i,根號(hào)下5+i
d根號(hào)下3-i,根號(hào)下3+i
e根號(hào)下3-1,-根號(hào)下3-i
數(shù)學(xué)人氣：481 ℃時(shí)間：2019-11-06 00:19:14
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