The locus of the moving point whose coordinates are given by et+e−t,et−e−t where t is a parameter, is

Let et+e−t,et≡h,kor h=et+e−t and k=et−e−tSquaring and subtracting, we get h2−k2=et+e−t2−et−e−t2=4Therefore, the locus is x2−y2=4.