If α+β=90∘\alpha + \beta = 90^\circα+β=90∘, which of the following is true?
sinα=cosβ\sin \alpha = \cos \betasinα=cosβ
tanα=tanβ\tan \alpha = \tan \betatanα=tanβ
sinα=sinβ\sin \alpha = \sin \betasinα=sinβ
cosα=−cosβ\cos \alpha = -\cos \betacosα=−cosβ