证明cos1/10-10来自/11大于零

cos(1/10-10/11360问答)∵ -π/2<1/10-10/绍冷时红律轻策红象眼11<π/2∴ cos(1/10-10/11)>0【如果】cos(1/10)-10/11∵ cosx=1-x²/2+(x^4)/4!-……当|x|<1时，cosx>1-x²/2∴ cos0.1=1-0.005>10/11∴ cos0.1-10/11>0